A viral health image making the rounds online shows a finger pointing at a dark reddish-purple patch on the skin, paired with the headline: “Doctors Reveal What These Bruises on Your Body Could Indicate.” The message taps into a common worry: bruises that appear without an obvious injury can be unsettling, and many people wonder if they signal a serious health problem.

Doctors say bruising is extremely common—and in most cases, it is harmless. A bruise forms when tiny blood vessels under the skin break and leak blood into surrounding tissues, typically after a bump, minor trauma, or repeated pressure. Sometimes the “injury” is so small you don’t remember it, especially on the legs or arms where we can easily knock into furniture or carry heavy objects.

Still, there are situations where bruising deserves attention. The key is to look at how often bruises appear, how large they are, whether they occur with other symptoms, and whether you are taking medications that affect bleeding.

Common and Usually Harmless Causes

1) Minor knocks you don’t notice
Many bruises happen during daily activity—walking, exercising, lifting, or playing sports. People often discover bruises later and assume they “appeared out of nowhere.”

2) Aging and fragile blood vessels
As we age, skin becomes thinner and blood vessels become more fragile. Older adults may bruise more easily, sometimes from very mild contact.

3) Certain medications and supplements
Doctors frequently see increased bruising in people who take blood thinners (such as warfarin), antiplatelet drugs (like aspirin), or even some anti-inflammatory pain relievers. Supplements such as fish oil, ginkgo, or high-dose vitamin E may also increase bruising in some people.

4) Intense exercise
Strenuous workouts can cause microscopic muscle tears or minor tissue damage that leads to bruising, especially after new or heavy training.

Nutritional and Medical Reasons Bruising Can Increase

Sometimes bruising points to changes inside the body, including:

Low vitamin levels
A lack of vitamin C can weaken blood vessel walls, and low vitamin K can impair clotting. Poor nutrition, restrictive diets, or gastrointestinal conditions that reduce absorption may contribute.

Iron-deficiency anemia
Although anemia doesn’t always cause bruising directly, it can occur alongside fatigue and pale skin. People who bruise easily and feel exhausted should consider medical evaluation.

Hormonal and connective tissue factors
Certain conditions that affect connective tissue may make skin and blood vessels more vulnerable. People may notice frequent bruises, flexible joints, or skin that stretches easily.

When Bruising Might Be a Red Flag

Doctors advise seeking medical attention if bruising comes with any of the following:

• Bruises that are large, painful, or appear frequently

• Bruising without any known trauma, especially if it keeps happening

• Easy bleeding from the gums or nose, or prolonged bleeding from minor cuts

• Tiny red or purple dots on the skin (petechiae), which may signal bleeding under the skin

• Blood in urine or stool, or black, tarry stools

• Unexplained fatigue, fever, or weight loss

• Bruising after starting a new medication

• Family history of bleeding disorders

In rare cases, frequent unexplained bruising can be linked to clotting disorders or blood-related illnesses. That does not mean bruising automatically signals cancer—but it does mean persistent, unexplained bruising should be evaluated rather than ignored.

What a Doctor May Check

If someone reports unusual bruising, doctors may ask about medications, diet, recent infections, family history, alcohol use, and recent changes in health. They may also recommend blood tests to examine platelet levels, clotting ability, and signs of anemia or inflammation. These tests help rule out more serious causes and identify treatable problems.