This Is Why Some People Bruise So Easily

You're probably no stranger to bruises — just ask the corner of your coffee table. But if you've started noticing bruises more often, either ones that form following the slightest acts of klutziness or seemingly out of the (black and) blue, you may be wondering if an underlying health issue is the culprit.

Bruising easily can happen to anyone at any age, but people assigned female at birth are generally at higher risk. "Men commonly have thicker skin and their bodies produce more collagen, which makes their blood vessels stronger and less prone to damage," Janice Johnston, MD, co-founder and chief medical officer of U.S. healthcare plan Redirect Health, tells LIVESTRONG.com.

Older people are much more susceptible to bruising easily, too, because skin becomes thinner and blood vessels become weaker as we age.

"Although most bruises are harmless and go away without treatment, easy bruising can sometimes be a sign of a more serious problem," Spencer Kroll, MD, a board-certified internal medicine specialist based in New Jersey, tells LIVESTRONG.com.

From taking certain medications to an underlying blood clotting disorder, figuring out exactly why you're bruising so easily can help you put together a successful treatment plan.

Below, a highlight reel of possible reasons behind your bruises to help you — with an assist from your doctor — get to the bottom of why you're always black and blue.

"As you age, your skin becomes thinner and you start to lose some of the fat on your body that would otherwise act as protection against injury," Dr. Johnston says. "Both of these conditions make you more susceptible to developing bruises."

On top of that, your blood vessels become more fragile, so even the slightest bump can leave a mark.

Following many years of sun exposure, sun-damaged skin can become thinner and blood vessel walls weaker, leading to more frequent and darker bruising, Dr. Johnston says.

Dermatologists call these bruises "actinic purpura" or "senile purpura." They appear as dark red splotches on the backs of hands and forearms and take longer to heal than your average bruise — usually, a few weeks. Taking certain medications (aspirin, steroids) and drinking alcohol can also encourage this type of bruising to form.

"Having a vitamin deficiency can hinder your body's ability to create blood clots, which can lead to bigger and darker bruises," Dr. Johnston says. Specifically, deficiencies in vitamins K and C can cause more severe and sometimes unexplainable bruising.

These forms of vitamin deficiencies are pretty rare — most people get enough of both through the foods they eat, but people with medical conditions that mess with how well the body absorbs nutrients (think: celiac disease, ulcerative colitis) may have a harder time getting enough from their diet alone.

"If an individual has a vitamin C deficiency, they might also experience bleeding gums, along with bruising and wounds that don't heal or take a longer period of time to heal," Dr. Johnston says.

Meanwhile, a vitamin K deficiency might translate into black stool and blood clots underneath the nails, in addition to being more susceptible to bruising.

Being short on iron can also cause you to bruise easily: "Iron is a key component needed for the body to make hemoglobin, an important part of red blood cells," Stefani Kappel, MD, a board-certified dermatologist based in Newport Beach, California, tells LIVESTRONG.com.

When there's not enough hemoglobin to go around, the body's red blood cells aren't able to function properly. Because they act as the body's oxygen-delivery service, your cells won't receive enough oxygen to thrive, making your skin more susceptible to bruising.

Other symptoms of an iron deficiency may include fatigue, dizziness and shortness of breath. People with heavy periods, who are pregnant or have gastrointestinal disorders are most at risk of not getting enough iron.

There are a number of medications and supplements that can increase your risk of bruising.

"Any medications that have a blood-thinning effect or reduce your blood's ability to create clots will trigger bigger bruises after experiencing impact on the body," Dr. Johnston says.

Common offenders include:

• Aspirin
• Ibuprofen
• Anticoagulant medications (heparin or warfarin, for example)
• Vitamin E
• Fish oil
• Gingko

Anti-inflammatory medications, like steroids (used to treat conditions such as asthma, hives, psoriasis and allergies), can also cause easy bruising, thanks to their skin-thinning effects.

The liver helps create proteins that enable blood to clot. "Without these proteins, excessive bleeding and bruising can occur," Dr. Johnston says.

Additional symptoms of liver disease include:

• Nausea
• Abdominal pain
• Appetite loss
• Darker urine
• Lighter stool
• Yellowing of the skin and eyes

There are more than 100 types of liver disease, according to the American Liver Foundation.

Various health conditions can cause your kidneys to act up, the two most common being high blood pressure and diabetes. "Kidney problems can impact the platelet count in the body, leading to easier bleeding and bruising," Dr. Johnston says.

Other symptoms to be aware of include:

• Reduced urination
• Chronic exhaustion
• Muscle cramps
• Itchy skin
• Seizures

The inflammatory disease process (rheumatoid arthritis, lupus and the like) can lead to a low platelet count and affect how well your blood clots following an injury.

"When your own immune system attacks blood cells or the actual blood vessels themselves, it increases the risk of bruising," Dr. Kappel says.

Besides bruising easily, you might also experience the following, per the U.S. National Library of Medicine:

• Chronic fatigue and general malaise
• Joint pain
• Rashes
• Fever

"There are many genetic blood abnormalities that can cause easy bruising," Dr. Kappel says. "Some are more serious than others."

Von Willebrand disease and hemophilia, for instance, are blood disorders caused by missing or defective clotting proteins (von Willebrand factor and factor VIII, respectively), putting you more at risk for bruising.

With platelet disorders, such as thrombocytopenia, there may be an underproduction or overproduction of platelets in the body, or platelets that don't work normally. "In the case of too few platelets, the body won't be able to control bleeding after experiencing physical trauma," Dr. Johnston says.

In addition to bruising easily, people with blood and platelet disorders might experience the following:

• Persistent nosebleeds
• Heavy menstrual bleeding
• Bleeding gums

It's much less common, but severe and unexplainable bruising can be a sign of a blood cancer, such as leukemia.

"Leukemias trigger white blood cell counts that are off the charts and a compensatory drop in platelets (which are necessary for clotting), putting blood cancer patients at a much higher risk for bruising," Dr. Kappel says.

Cancer-related bruises tend to appear in odd places, like the torso or hands.

Other symptoms of blood cancers may include the following, per the American Society of Hematology:

• Chronic fatigue
• Pale skin
• Headaches
• Swollen or bleeding gums
• Unexplainable weight loss
• Fever
• Excessive sweating

There are a number of signs to be on the lookout for when it comes to bruising — primarily, if you bruise easily from the slightest trauma (say, bumping your knee) or frequently for no reason, especially if you experience severe pain and swelling in addition to bruises.

"Generally, bruises should fade completely in a couple of weeks," Dr. Johnston says. "If your bruise doesn't heal after roughly three to four weeks, you should seek medical attention because it could be a sign of a more serious medical issue."

You should also seek medical attention if your bruises appear on parts of your body where injuries are unlikely to occur, like your torso, back, face or on the backs of your hands. Ditto if they start to appear after you've started a new medication.

In most of these cases, your doctor will likely run tests to determine why you're bruising so easily, such as tests that measure how quickly your blood clots or determine your blood platelet levels.

"If bruising is associated with any bleeding — nosebleeds, excessive gum bleeding, rectal or urinary bleeding — you should consult with your doctor immediately," Dr. Kroll says.