Factitious Disorder: Why People Fake Serious Illness

Factitious Disorder: Why People Fake Serious Illness


[INTRO] Did you ever fake being sick as a kid? Maybe you were just such a goody-two-shoes
that your parents didn’t think you’d actually lie. Maybe you had it down to a science: run the
thermometer under hot water in the bathroom sink, do some jumping jacks, get hot and sweaty,
and then climb back under the covers and put on your cutest pout. Or maybe you were lucky enough to actually
get your Hogwarts letter and you always kept a Skiving Snackbox or two on hand. If so, I’m super jealous. In any case … why’d you do it? To get out of a test? To avoid that big presentation? Because your parents always made you a giant
ice cream sundae on days when you were feeling lousy? That’s what’s known as malingering: faking
symptoms of illness for some sort of clear material benefit. But for people with factitious disorder, faking
illness isn’t quite so straightforward: they fake symptoms of illness and take on
the role of a sick person, but they do it without obvious external motivation. Historically and in pop culture, it’s usually
called Munchausen syndrome, after a 17th century baron who had a thing for embellishing stories. People with this disorder do all sorts of
things to pull off the ruse: they might lie about their medical history, fake test results,
even cause physical harm to themselves to make it look like they have a disease or condition. They can end up doing things that are pretty
extreme, which is probably why the disorder has shown up in almost every medical drama
on TV. But for the people living with it, the consequences
can be a lot more severe than like a scathing tongue-lashing from Dr. House. In one study that followed 20 people living
with factitious disorder, four of the subjects died because of disorder-related behavior. And even if people with factitious disorder
don’t harm themselves in the process of faking their symptoms, they can still be harmed
by unnecessary medical procedures or find themselves bankrupted by medical bills and
missing work. There’s a variant of this disorder that’s
even worse: people diagnosed with factitious disorder imposed on another fake symptoms
in another person, usually a child or an adult dependent. In those cases, the first step is to protect
the victim, usually by removing them from the care of the person with the disorder. By now, you’re probably wondering why would
anyone go to such lengths to seem sick. Well, psychologists have wondered that, too. It’s worth noting that most of the research
on factitious disorder comes from case studies. It’s hard to find subjects for an empirical
study, because if patients won’t admit they’re faking — and most of them won’t — the
only way to really prove it is with their medical records. And that violates patient confidentiality. Still, a lot of cases have been documented,
and the consensus among researchers is that the goal is to assume what they call a “sick
role.” Think about the last time you were sick. How did your friends and family treat you? I’m sure feeling sick wasn’t fun, but
the way other people treated you was probably kinda nice. We have different social expectations for
people who are ill. They’re often given more attention and sympathy,
and other people try to help them out. That treatment is what people with factitious
disorder seem to crave. People with the disorder are also generally
experiencing psychological distress, and faking physical symptoms can be a way to get attention
and care. But even though faking the symptoms might
be conscious, the motivation behind it and that psychological distress are usually unconscious. Case studies show that a lot of people with
factitious disorder experienced childhood trauma, illness, loss, or neglect. It is possible to treat factitious disorder. Seeing a therapist to talk about the underlying
distress can help. The biggest problem is diagnosing the disorder
in the first place. It’s a tricky balance: obviously doctors
don’t want to perform risky procedures on people who don’t need them … but they
also don’t want to withhold them from people who do. There are clues to watch out for, though. For example, people with factitious disorder
often have hopped from doctor to doctor. They tend to be pretty calm about scary symptoms,
and they’re willing to undergo some serious procedures. And a lot of the time, all those tests and
procedures … just don’t do much to help. Of course, there are also people who fit that
description who are not faking. So, it’s complicated. Even once it’s clear that they have factitious
disorder, confronting patients doesn’t always work. Studies have shown that only 15-20% of people
with factitious disorder will admit that they’re faking. Most of them just go find another doctor. The best approach seems to be to offer an
alternative that will encourage the patient to seek psychological help without having
to admit that they faked their symptoms. They’re told that while the doctors work
on their condition, a psychologist might also help them get better. That way, their therapist can work with them
on understanding the underlying distress that caused them to seek the “sick role” in
the first place. And hopefully, eventually, they will stop
needing to fake it. Thanks for watching this episode of SciShow
Psych, and thanks to our patrons on Patreon for helping us make this show. To learn more, and get cool rewards like access
to a monthly livestream with the crew, you can go to patreon.com/scishow. And don’t forget to go to youtube.com/scishowpsych
and subscribe!

These Ant Paramedics Save Their Injured Comrades

These Ant Paramedics Save Their Injured Comrades


♪Intro♪ If you’re ever seriously hurt, you can probably
go to a hospital and get help. But animals don’t have doctors. If they’re injured, wounds can get infected
pretty quickly or mean impending doom. Except… that might not necessarily be true
for one species of ant. In a paper published this week, researchers
from Germany have discovered that the African Matabele ants tend to each other’s open
wounds after vicious battles with termites. And they think it’s the first time a behavior
like this has ever been observed in insects. Two to four times every day, Matabele ants
hunt termites. A scout ant finds a vulnerable nest of termites
and then leads a raiding party back to it. But termites have powerful jaws, called mandibles,
so these raids are pretty dangerous for the ants. They often end up with one or more of their
six legs bitten off. Scientists already knew that these wounded
ants secrete pheromones from glands in their mandibles that act as calls for help, attracting
their friends to carry them home. And now, thanks to a combination of lab and
field experiments, we also know what happens next. Very badly injured ants — who have lost
almost all of their limbs — are left behind, because they thrash around so much that helper
ants can’t carry them. Ants that are less badly injured — like
if they’re missing one or two legs — keep still, cooperate with their rescuers, and
are more likely to be carried back. This keeps resources from being wasted on
lost causes. Once an injured ant gets home, other ants
lick their wounds for several minutes. Ants don’t really have tongues, but they
carefully clean the injuries with their mouthparts. According to these experiments, ants that
lose limbs and don’t receive this treatment have about an 80% chance of dying. But with the licking, that number drops to
10%. The researchers think this treatment helps
reduce the chance of infection in open wounds, removing dirt and debris that could carry
pathogens. And while this hasn’t been tested yet, it’s
possible the ants could be applying some sort of antimicrobial substance as well. Once they heal up, ants that still have four
or five legs left can get around just fine and contribute to the colony. So this treatment isn’t just out of the
goodness of their hearts — it’s a useful adaptation. Those wounded veterans are still expected
to earn their keep. Ant medicine may be full of surprises, but
we’re still learning a lot about human medicine, too. And a study published in the journal Science
this month gleaned some new insight into brain disorders. Many medical conditions can be diagnosed based
on physical signs, like a rash or a tumor. But psychiatric conditions are different. Doctors can’t spot them on a brain scan;
they have to be diagnosed based on feelings and behaviors. We know that certain gene variations are linked
to risks for certain psychiatric disorders, but that part of biology involves a lot of
questions, and not very many answers. All of your cells have the same DNA, so sequencing
your genome can reveal what gene variants you have. But analyzing all the RNA in a cell, which
is called a transcriptome, actually shows which genes are being expressed. That’s because the information stored in
DNA is decoded into RNA to make all the different proteins our bodies need. Cells in different organs need different proteins,
and therefore different active genes, to do their jobs. But other things, like environments you’ve
been exposed to, could affect gene expression too — including genes in brain cells, where
tiny chemical changes can affect how you think, feel, and act. This new study combined data from nine previous
studies to form a meta-analysis of 700 brain tissue samples from deceased people. Specifically, the researchers were looking
at RNA in cerebral cortex tissue — the surface structure in the brain that’s involved in
a lot of information processing and decision making. The tissue samples came from patients with
autism, schizophrenia, bipolar disorder, depression, and alcoholism, and some brains of people
without any diagnosed disorders for comparison. Using a lot of math, the scientists used all
this transcriptome data to look for patterns of gene expression. These are all different disorders with different
symptoms, so it would make sense to think that their causes and effects in brain cells
would vary, as well. But learning if and how these conditions overlap
might give scientists new hints about how to help these patients. And some patterns the researchers found caught
them by surprise. For instance, bipolar disorder and depression
were fairly distinct, even though they’re both considered mood disorders and share some
symptoms. Alcoholism also had basically no overlap with
any of these other disorders, despite previous studies that suggested that alcoholism and
depression might share some genetic risk factors. Schizophrenia and autism, on the other hand,
showed some similarities. With both disorders, patients seemed to express
fewer genes for communication between neurons and more genes related to inflammation. And inflammation-related genes were extra
active in the autism brain samples, adding to evidence that gene overexpression could
play a role in that condition. There are other small results too, but no
huge takeaways yet. Mostly, this study is another step toward
learning how brain functions can go wrong. Transcriptome research won’t actually help
with diagnoses and treatments until we do a lot more of it, and on more specific parts
of human brains. But by gradually learning about how psychiatric
disorders might affect brains biologically, researchers hope to develop more effective
treatments someday. Thanks for joining me for SciShow News, and
a special thanks to Patreon President of Space Matthew Brant. Without Matthew and all of our patrons on
Patreons, we wouldn’t be able to make SciShow and bring you all up to date science news. ♪Outro♪

How a Sick Chimp Led to a Global Pandemic: The Rise of HIV

How a Sick Chimp Led to a Global Pandemic: The Rise of HIV


Here at SciShow, we talk a lot about the fascinating,
complicated, and often very weird stories of discovery and collaboration that led to
the science we know today. But one of the strangest is something we haven’t
covered in much detail before, and it’s a biggie: the decades it took to figure out
exactly what HIV and AIDS were, and how to prevent and treat them. Since the start of the AIDS crisis, some 70
million people have been infected with HIV, and 35 million of those people have died. Both those numbers are staggering in their
own way, and together, they tell the story of a disease that has led to an incredible
amount of loss, but also one that — if you’re lucky enough to have access to the right medicines
— is no longer a death sentence. So, in honor of World AIDS Day on December
1, we want to tell you that story. There’s a lot to cover, so we’ll do it
in two parts. This episode, we’ll go over how we figured
out what HIV is, when the infection morphs into AIDS, and where we think the virus came
from. Next time, we’ll look back to the earliest
treatments, the arrival of antiretroviral drugs, which were complete game-changers,
and go over the creative ways scientists are now thinking about prevention and possibly
even a cure. But first, the basics. HIV, or human immunodeficiency virus, is a
retrovirus that infects immune cells, most notably what are known as CD4 T cells. The “retrovirus” part just means that
the virus uses RNA — DNA’s more wily, less stable cousin — as its genetic material,
and that once HIV infects a cell, it makes a DNA version of its genome with a special
enzyme, then inserts that DNA into the host genome. If that sounds sneaky — well, it is. And it’s part of why HIV has been so difficult
to treat, which we’ll talk about more next time. Now, those CD4 T cells that HIV infects and
ultimately kills are a kind of white blood cell known as ‘helper’ T cells. When they recognize a threat, they pump out
proteins that help coordinate a bunch of different immune responses. You definitely want them around. HIV is spread by bodily fluids, including
blood, semen, vaginal fluid, and breast milk. That’s why HIV can be transmitted through
sex, dirty needles, breastfeeding, and any other swapping of fluids you might do — with
a major exception: saliva isn’t one of those fluids. Saliva is full of other stuff that prevents
HIV from being infectious, like antibodies and a bunch of antimicrobial proteins. So unless there’s a lot of blood in your
saliva for some reason, it can’t transmit HIV. When someone is first infected, they might
feel like they have a bout of the flu, with a fever, headache, rash, sore throat, and
muscle and joint pain. That’s because the virus is infecting lots
of cells and the immune system is trying to fight it off. But within a few weeks those symptoms pass
because by then the person has specific antibodies that can keep the virus from running totally
rampant. After that, they usually feel fine for a long
time — in many cases, a really long time, like several decades. Until, one day, they don’t, because the
virus has finally killed off too many T cells, leaving the body unable to properly defend
itself against pathogens — anything that might be dangerous or infectious. That’s when someone is said to have AIDS,
or acquired immune deficiency syndrome. Usually AIDS is diagnosed once the person’s
T cell count falls below 200 cells per microliter of blood, which is well below the normal 500-1500,
or if they develop what’s called an opportunistic infection. These are infections that anyone with a reasonably
strong immune system would be able to fight off, easy-peasy. But because HIV has obliterated most of their
T cells, AIDS patients get sick. And, they can die. Most of the time it’s an opportunistic infection
that killed them. So, some of that was probably familiar to
you, but pretend for a moment that you’ve never heard of HIV or anything else I just
mentioned. Because back in the ‘80s, we didn’t know
these basic facts. All doctors knew was that suddenly, healthy
young gay men were developing extremely rare infections and cancers — and, it was killing
them. One of the first people to notice the pattern
was an immunologist at UCLA. Between the fall of 1980 and the following
spring, he saw a string of five patients, all gay men in their 20s or 30s, with an unusual
kind of pneumonia. There was a fungus growing inside their lungs. Normally, the fungus was totally harmless
and would never infect the lungs, but in these men it had, and it was making it hard for
them to breathe. The patients also had oral thrush — basically
yeast infections in their mouths — and few CD4 T cells. By June, when the immunologist wrote up the
results for the CDC’s weekly Mortality and Morbidity report, two patients had died. A month later, a dermatologist in New York
chimed in with a similarly disturbing report, this time with Kaposi’s sarcoma, a rare
cancer where patients develop blotchy purple lesions on their skin. In two and a half years, 26 young gay men
in New York and LA had been diagnosed with Kaposi’s. Some also had the weird fungal pneumonia,
and 8 had died. It’s hard to imagine now, but at this point,
scientists had no idea what was making people sick. They didn’t know if it was some sort of
toxin or a pathogen. And if it was an infection of some kind, they
didn’t know how it was spreading. That meant they couldn’t warn people about
how to protect themselves. The association with gay men, though, was
certainly striking, and early on, many called the mystery disease GRID, for gay-related
immune deficiency. Lots of people would talk about it as the
“gay cancer” or “gay plague.” But the disease wasn’t limited to gay men. It was turning up in hemophiliacs — people
whose blood doesn’t clot properly and are treated with clotting factors taken from other
people’s blood. Doctors were also seeing cases in IV drug
users, women, infants, and heterosexual men. In particular, 20 recent immigrants from Haiti
had gotten sick, and none said they were gay. Those clues were important, because they told
scientists the disease — which had finally been given the name AIDS — was probably
infectious, and probably transmitted by blood. There were other diseases that spread in similar
ways, like hepatitis B. So in March of 1983, the CDC issued a warning
that doctors needed to be careful about blood transfusions, and that the disease seemed
to spread through both gay and straight sex. Debates about the specifics, including whether
it could spread through saliva, would happen later. But what was the infectious agent? The race was on for scientists to figure out
what was causing the disease. French molecular biologist Luc Montagnier
suspected a virus because at the time, the blood products hemophiliacs used were filtered
for things like bacteria and fungi. But viruses were too small to catch. So along with his colleague Françoise Barré-Sinoussi,
he searched cells taken from AIDS patients and found a retrovirus. Around the same time, Robert Gallo at the
NIH in the US also identified a retrovirus in samples from AIDS patients. Both groups published their work in May 1983,
and shortly afterward another team found yet another retrovirus. All the viruses had been given different names,
and at first, it’s wasn’t totally obvious that they were the same thing. But they were, and in 1986, the cause of AIDS
had been given an official name: HIV. So, HIV was the problem, but where had it
come from, and why had the epidemic struck now, in the decade of big hair and Michael
Jackson? While some researchers were scrambling to
identify whatever it was that made AIDS infectious, others noticed that macaque monkeys also seemed
to suffer from an AIDS-like disease. One group decided to take some blood samples
from these sick monkeys, and in 1985 they found a virus that was similar to HIV. It was eventually called SIV, for simian immunodeficiency
virus. Researchers started to think that HIV might
have come from our primate relatives, jumping the species barrier. After a lot of work, they figured out that
the virus behind the epidemic was very similar to the chimpanzee version of SIV, and they
were the ones who had passed it to us. But how exactly? There’s no real way to put this delicately,
but most scientists agree that the reason why SIV made the leap into humans — what’s
called a spillover — is because we had a taste for bushmeat, or wild game. In this case, monkeys and chimps. This is known as the cut-hunter hypothesis. In the course of butchering a chimpanzee,
some SIV-infected chimp blood enters a small cut on the hunter’s hand. Or, a bit of blood splatters in their mouth. The virus is close enough to human biology
to infect the hunter, and over time, if the hunter passes the virus along to enough people,
it evolves into the HIV we know today. Spillovers like these happened many times
— we can tell because the virus mutates quickly, and by looking at genetic differences,
we can identify multiple lineages of the virus, each one corresponding to a spillover. We’ve traced the current epidemic to just
one of these, called ‘M’ for main. By analyzing chimpanzee pee and poop, researchers
think the chimps who passed that version of the virus to us lived in southwestern Cameroon,
in the forests near the Congo. And based on the oldest blood samples we can
find that we now know have HIV in them, which are from 1959 and 1960, scientists estimate
that HIV-1 first infected humans around 1908. If that seems like a long time ago, well,
it takes a while for a virus to take off. By the 1920s, it’s thought that the virus
traveled downriver — in a person, of course — to the burgeoning city of Kinshasa, then
known as the Belgian colonial city of Leopoldville. There weren’t many women around other than
prostitutes, so experts think HIV spread that way, and possibly through injectable drugs
the colonists used to treat some tropical and venereal diseases. This was before disposable syringes, and nurses
were trying to treat lots of people with just a few of them, so the syringes may have only
been rinsed with alcohol before being used on the next patient. So the very methods meant to stop the spread
of disease may have actually been
encouraging it. With time, infected people in Kinshasa left
to go to other places, and they did the unavoidable: they brought the virus with them. Because the virus mutates so quickly, we can
group the viruses into 9 different subtypes and get a sense of how HIV traveled around
the world from Central Africa. Several subtypes spread to other parts of
Africa. Subtype C went south and then landed in India. Subtype B went to Haiti — and then, through
several quirks of history, came to the US. First, in 1960, when the Belgians left the
Congo, French-speaking Haitians started to arrive in the Congo to work as doctors, lawyers,
and other professionals. But with the creation of Zaire in 1965, the
immigrants felt unwelcome, so they went back to Haiti, bringing HIV with them. There, HIV expanded especially quickly, possibly
because of a plasmapheresis center where people could get paid to donate their blood plasma. The center used a machine that mixed the blood
of different donors, allowing viruses to transfer. By 1982, nearly 8 percent of a group of young
mothers in a Port-au-Prince slum were HIV-positive — an astoundingly high number. HIV is thought to have entered the US around
1969, with just one infected person or unit of plasma from Haiti. It took about a decade for anyone to notice,
but by then it was too late. The epidemic had begun, and HIV was not only
in the Americas, but Europe and Asia, too. And now that it was here, we needed to figure
out how to fight it. But we’ll get to that in the next episode
of this mini-series. In the meantime, thanks for watching this
episode of SciShow, and if you want to learn more about HIV and all kinds of other science,
you can go to youtube.com/scishow and subscribe.

Immigration Relief for Victims of Human Trafficking

Immigration Relief for Victims of Human Trafficking


Human Trafficking is a form of modern-day
slavery. Victims are often lured under the false pretenses of good jobs and better lives
and then forced to work under brutal and inhumane conditions. Many believe that human trafficking
is a problem that only occurs in other countries. But human trafficking also happens here in
our own neighborhoods. Human trafficking is one of the most heinous
crimes that we investigate. Where traffickers prey on vulnerable populations. When I learned I was coming to America. I
was happy I was coming to America. Oh, it’s America. It’s the land of opportunity.
And I grabbed it. The opportunity. To get. To come here. They told me they will take care of everything,
paperwork and everything; I wouldn’t have to worry about it. They use them as a commodity, holding them
against their will using force, fraud of coercion for the purposes of forced labor or commercial
sex. She asked for my passport. She said where
is your, do you have your passport, I said, yes I have it. And then she take it. “I will
take care of this” and I trusted her. When I was with them I never thought that
I will leave them and will have my freedom again, for a very long time. Many victims don’t realize that they have
rights and protections in the United States. One such protection that victims of human
trafficking may be eligible for is the T Visa. The T nonimmigrant status (or T Visa) provides
immigration protection to victims of severe forms of trafficking who assist law enforcement
in the investigation and prosecution of human trafficking cases. Often, victims are afraid to come forward
and worry that law enforcement will bring them back to their traffickers. At the traffic lights, those cameras. They
would point those to us, to me, and tell me that “you see those camera?” The police are
checking on you, so if you try to escape or try to run away they will still catch you. Every time we go out, when you go out be careful
of the police they might arrest you, or don’t find any friend, don’t talk to neighbor, don’t
talk to people They going to call the police and I was scared I didn’t have nowhere to
go at that time. My role as a special agent investigating these
crimes is to identify someone whose been a victim of human trafficking, assist that victim,
rescuing them from the situation, helping them connect with different services that
they have. That they regain their freedom of will. They told me that, “don’t worry, just tell
the truth, just tell what’s going on and we will help you.” When the FBI asked me if I wanted to leave
with them or if I wanted to stay back, and when I told them that I wanted to leave with
them, and they told me “ok, let’s go up and collect your things.” That’s when I felt like
I felt a little bit relived knowing that I’m going to leave that family. Once law enforcement is involved, victims
can petition for a T Visa through USCIS. Victims are not required to be in legal immigration
status to be eligible for a T Visa, but they must, Be a victim of a severe form of trafficking
in persons. Be physically present in the United States
on account of the trafficking. Comply with any reasonable requests for assistance
in the investigation or prosecution, or be under the age of 18, or Suffer extreme hardship involving unusual
and severe harm if removed from the United States. To apply for a T nonimmigrant status, applicants
must file Form I-914, Application for T Nonimmigrant Status. Qualifying family members may also
be eligible to apply for immigration benefits. Visit www.uscis.gov/humantrafficking, or call
the National Human Trafficking Resource Center at 1-888-373-7888 for information on how to
get help. If USCIS grants T nonimmigrant status the
applicant will automatically be eligible to work. The T nonimmigrant visa is valid for
four years and a visa holder may be eligible to apply for permanent residence with a green
card after three years in a T nonimmigrant status. Human trafficking is a particularly difficult
crime to investigate because victims of trafficking don’t normally self-identify and also because
it’s a crime that’s hidden in plain sight. Traffickers operate in an underground society,
they isolate their victims, they often times take their identity documents. They assure
that there’s no communication between family and friends. So it’s hard for us to identify those victims.
Which is why we often ask the public to be aware of those different indicators, and if
they see them to report that suspicious activity. She started telling us not to talk to anybody.
we’re not supposed to talk to anybody or we’re not supposed to use her phone to call anybody. And then days pass and pass and weeks then
I realize that I haven’t gotten a day off, I haven’t stopped working. I was thinking, who’s gonna believe me? What
I’m thinking is, she has the paper. She’s a citizen. And me I’m just like, I don’t have
any paperwork. I was feeling they’re gonna believe her, not me. I used to work 7 days a week. I didn’t have
any days off. And we had to stay up late, until around 3. And we had to wake, to be
up and ready by 6 in the morning. Every single day. There are several human trafficking indicators
that people can be aware of. Do you know someone who, Isn’t allowed to
control or possess his or her identification and travel documents? Is forced to perform
sexual acts? Cannot freely move, contact family or friends, or socialize? Has been threatened that they or their family
will be harmed if they try to escape? Has been harmed or deprived of food, water, sleep,
medical care or other life necessities? Is the victim a juvenile engaged in commercial
sex? If you do see any of these indicators, call
the Human Trafficking Resource Center at 1-888-373-7888. You can also contact the center for help in
getting a T Visa. I start working with my lawyer telling my
story, working to apply for T-visa, now I have my T-visa. Now I still continue working
without doubt. Now I’m looking forward to applying for my green card. I was so happy in that time. Finally I’m legal,
I can be able to find a job now. I got my green card in July. I’m still working
at the same place. I’ve been working since 2009. I’m planning to go home soon for a visit.
And then when I come back then I’d like to start school. If there was a message to tell victims it
would be, do not be afraid to come forward, call 911 if you are in harms-way, to know
that you have rights under the law in the US and if you see suspicious activity to please
report it. Together, law enforcement, community organizations,
and people like you can help end human trafficking. Call the National Human Trafficking Resource
center at 1-888-373-7888 to report human trafficking and for other inquiries. For more information,
visit www.uscis.gov/humantrafficking.

How Does Icing an Injury Help?

How Does Icing an Injury Help?


Probably one of the first things you do when
you bang your knee or twist your ankle is put an ice pack on the injury. You probably know that that can help reduce
swelling and dull the pain, especially within the first couple days after you get hurt. But why interfere with the way your body’s
trying to naturally heal itself? When you pull a muscle, stretch a tendon,
or burst a blood vessel, that triggers your body’s inflammatory response: it sends a
bunch of blood cells and fluids to repair the damage. And that is an important part of the healing
process. The problem is, your inflammatory response
tends to overreact. If you’ve ever gotten hay fever in the spring
and felt like your eyes and nose were going to melt off your face, you know what I’m
talkin’ about. Too much swelling can cause a bit of a traffic
jam with all the fluids rushing in, which can cut off nearby cells from getting the
oxygen they need to keep functioning. And that is where icing an injury, also known
as cryotherapy, can help. When you put ice on a part of your body that’s
inflamed, the tissues and blood vessels contract, limiting how much blood and other fluids can
get to the area and bringing down the swelling. Cold can also slow down the cells’ metabolism,
so they use the oxygen they do have more slowly and don’t die. If it’s at a joint, like if you sprain your
ankle, you’ll be able to use it a little more, and maybe do some rehab exercises. But if you leave an ice pack on for too long,
it can actually do more harm than good. If the injury site gets too cold, your body
will flood in even more blood cells and fluids, trying to warm it back up, even if you’re
still using the ice pack. This renewed blood flow is called hyperemia,
and it’s why doctors say it’s generally good to limit cryotherapy to about 10 or 20
minutes at a time. After that, let your injury warm up for 10
minutes or so before putting the ice pack back on. Ice can also reduce the pain you feel. When they get cold, the ions that carry messages
around between neurons have a harder time getting around, reducing the pain signals
going to your brain. Also reducing lots of other kinds of signals,
which is what numbness is. So when you get hurt, it is important to let
your body do its thing and heal. Ice just helps make sure your body doesn’t
overreact, and keeps you a little more comfortable in the process. Thanks to all of our Patreon patrons who keep
these answers coming, and for more on the science of injuries, check out this other
SciShow video where Michael explains why papercuts hurt so dang much.