By Mollie Bloudoff-Indelicato, Everyday Health
Bruises - the result of playground shenanigans and thwacked funny bones, unfortunate falls and bumps on the furniture - are a curiosity to behold. They're black and blue (and green and yellow and red) and occur when blood vessels break and discolor the skin. Sometimes they go away quickly, and sometimes they last for weeks.
There are three types of bruises - skin, muscle and bone - which means you can bruise pretty much anything on your body. Just ask the patient profiled in "Snap without crackle or pop: a rude awakening. A case history of penile fracture," an article published in the Journal of Accident & Emergency Medicine. Ouch.
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So why do we bruise? And who bruises easiest? Read on to learn more.
1. Brunette Advantage: Redheads May Bruise More Easily
Redheaded women may be more susceptible to bruising than brunettes or women with black hair, according to a 2006 study funded by the National Institutes of Health. Doctors have long reported anecdotally that their red-haired patients were more likely to bruise after a procedure. Researchers at the University of Louisville in Kentucky decided to investigate. The team gave questionnaires to 25 natural redheads and 26 naturally dark-haired female volunteers; the redheaded women were much more likely to report that they bruised easily.
The scientists couldn't come up with a rationale for the finding because the women in the study were of similar heights, weights, and ages, and none had blood-clotting issues. But the difference could have something to do with a mutation of the MC1R gene, which helps control pigment formation and causes hair to be red. Or, it could mean that those 25 women happened to complain more. You decide.
2. Hickeys: The 'Love' Bruise
Hickeys conjure up images of teenagers making out in the backseats of cars, but they may be considered sexual abuse if they're unwanted or show up on a minor, according to Stanford University Hospital. The technical term for a hickey is "suction ecchymosis," and you get them when sucking breaks little capillaries near the surface of the skin, causing bruise-like marks that can last for days.
3. Black and Blue and Buried: You Can Bruise After Death
Even death doesn't exempt you from the burden of bruises. The technical term for the injury in the deceased is "florid postmortem extravasation of blood" or, in layman's terms, bruising after you've kicked the bucket.
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In one case, clinicians were disturbed to find that a corpse exhumed for an autopsy had horrible facial bruises. Because the woman was 98 years old at her passing, the skin around her head and neck was very fragile and could have bruised easily. Officials suspected foul play, and two men eventually admitted to digging up the grave with crowbars and shovels, which may have caused the bruising, according to a 1998 article in the American Journal of Forensic Medicine Pathology.
4. Gender Bias: Women May Bruise More Than Men
Men may get a reprieve from bruises because their skin is generally thicker (anatomically speaking, of course!) than that of their female counterparts. Thicker skin provides more of a barrier between the outside world and fragile blood vessels. Men also have a higher collagen density than women, and collagen strengthens blood vessels, preventing them from breaking. Still, these are just theories. There aren't any definitive studies out there to settle the matter. Some doctors also say that women bruise more easily than men, but women are probably more likely to notice and report bruises.
5. Bruised Egos: You Bruise More as You Age
Sorry Baby Boomers, time has not been good for your skin. As we age, our skin gets thinner and our blood vessels more prone to breakage. This means that people pushing 50 are much more likely to bruise. In fact, those in the older set may even experience spontaneous bruising.
That's right, you don't need to injure yourself to get a bruise. The term for this is "senile purpura," and it occurs when tiny blood vessels spontaneously start to leak underneath the skin, said Lily Clark, MD, a dermatologist in New York City.
6. The Hangover: Alcohol and Bruising
Ever wake up the morning after a crazy night out and see a couple of shiners looking back at you in the mirror? Drinking lots of alcohol over a long period reduces your body's store of vitamin A, which helps keep skin healthy and could make you more bruise-able. Drunk people are also more likely to bump into things, putting them at a higher risk for bruising. If you already have bruises, vitamin A deficiency will make the symptoms last longer because, scientists believe, vitamin A is a factor in wound repair.
7. Black, Blue, Brown, Yellow: What Does Bruise Color Mean?
Typically, a bruise begins as a reddish color, turns a blue-purple and green-yellow color and then turns back to normal looking skin. But multiple studies show that people aren't great at determining and describing bruise color. As you get older, your perception of the color yellow in bruises decreases -about 1 percent per year. This is important because doctors have been known to use bruise color as a diagnostic tool. Bruise color was also significant in domestic abuse cases, where it was formerly used to determine the time of a beating, though now we know it's not as accurate as once thought.
8. Torture or Treatment: Bruises as Migraine Therapy
Don't try this at home, folks. Purposeful bruising is part of an ancient Southeast Asian tradition called Gua-sha or "coin rubbing." The practice is a dermabrasive therapy, and it's believed to soothe headaches, fever, and the flu. Practitioners lubricate the skin on either side of the spine and ribs with medicinal oils and then rub it with a coin, causing red marks and oftentimes bruising. If done correctly, "this traditional health practice is said to release excess 'wind' or energy considered responsible for illness."
9. Scientific Bruising: Inflicting Bruises in the Name of Research
How do scientists study bruising in the lab? In a 2010 study done by some researchers from The London School of Medicine and Dentistry,"bruises were produced on the upper arms of 11 subjects by a suction pump." And in 2002, 19 subjects stepped up to the plate and took one for the team: "Bruises were produced mechanically on the forearms of subjects with a device composed of a free-falling weighted plunger." No pain, no scientific gain!
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This article originally appeared on EverydayHealth.com: 9 Weird Facts About Bruises