Who among us hasn’t woken up one morning with a giant, grotesque bruise taking shape on our arm or leg, yet with no memory of an injury that could have caused it? I know I’ve often asked friends and coworkers, “Ooh, how’d you get that shiner?” And more often than not, the response is a decidedly lackadaisical “Eh, who knows?” When you’re saddled with a sizable contusion, shouldn’t you at least remember the injury that caused it?
Bruises, the purplish swellings that happen when delicate capillaries meet blunt-force trauma, are an unpleasant fact of life (especially active, athletic, or clumsy lives). Bruises aren’t usually dangerous—the body eventually reabsorbs the blood that leaks into the surrounding tissues—but they can be disconcerting when they seem to show up without rhyme or reason.
According to the Mayo Clinic, random and unexplained bruising is common, especially among older people. Although we usually think of bruises as the result of painful bangs and bumps, they often show up after much less provocation than that. Any time the soft tissues in the body are injured, whether close to the surface of the skin or deep below, blood vessels can rupture and a bruise can form. For people who are prone to bruising, even a slight bump is enough to leave a mark.
The Usual Suspects
There are several simple reasons, and many not-so-simple ones, why some people are more bruiseable than others. For people who consider themselves bruise magnets, the most common cause is thin skin. Predictably, most bruises appear on the arms and legs, which usually have a thinner layer of protective fat than other areas of the body and therefore less padding to absorb the shock of an impact. Some medications can also alter skin’s thickness. Corticosteroids (like the topical creams prescribed for eczema and other dermatological conditions) can lead to thinning skin and increased bruising. The thin-skin theory also explains why women are more likely to bruise easily than men are (women have thinner skin), and why people bruise more frequently as they age (older people have thinner fat reserves under their skin).
Anything that interferes with blood’s viscosity or ability to clot can also result in excessive bruising. People with blood disorders, such as hemophilia, are usually prone to bruising, since the slightest touch can injure blood vessels and cause uncontrollable bleeds. Even people without chronic diseases can have impaired blood clotting, though. Drugs like aspirin and warfarin, as well as dietary supplements, such as ginkgo biloba and fish oil, hinder clotting and cause bruising. Deficiency in vitamins C and K can also be the culprit. Vitamin K plays an important role in clotting and vitamin C helps form strong capillary walls.
Repeated and excessive bruising can sometimes (albeit rarely) be a sign of serious illness. Bruises naturally take about two weeks to fade, so it’s wise to be cautious about bruises that don’t lessen during that time. It’s also unusual to encounter bruises near the eyes or on parts of the body that don’t typically get bumped and knocked around (like the upper back, the face, or the chest), so those are cause for suspicion as well.
Although it’s normal for bruises to be uncomfortable and sensitive to touch, bruises that are unusually large or especially painful should always be checked out, especially if they occur regularly. Bruises accompanied by bleeding elsewhere in the body, whether from the gums, from the nose, or in the stool, could be a sign of a bleeding condition elsewhere in the body. They could also indicate a problem with your blood’s platelets, components that facilitate clotting. Some blood and platelet disorders signify an infection or a larger problem, like leukemia or an autoimmune disorder, and some are diseases unto themselves. For example, von Willebrand disease, thought to be the most common inherited blood disorder in the United States, is marked by unexplained bruising and excessive bleeding, usually from the nose or gums. Luckily, serious illnesses that are marked by serious bruising are mostly treatable.
There’s no way to completely prevent bruises from forming, but it’s possible to lessen their severity, as long as you’re aware of the bruise-causing injury when it happens. The best way to reduce the size of a growing bruise is to apply ice to the area right away. The cold reduces the amount of blood that flows to the injured region, reducing the swelling and the amount of blood that will leak out of blood vessels into the surrounding tissues. Another way to reduce a bruise’s severity is to elevate the area immediately after the injury to prevent blood from pooling.
Bruises are bound to happen—whether you’re biking, hiking, or just relaxing at home. It’s not even unusual to wake up with a bruise after sleeping. Odds are good that no matter how prone you are to bruising, it’s nothing to be concerned about, and the best course of action is simply to eat a healthy diet and try to avoid bumping into things. Instead of worrying about how easily you bruise, it’s better to spend that time looking for pantyhose and long sleeves to cover the evidence.