Easy Bruising: Why You Bruise Easily

How a bruise forms

A bruise (contusion) is blood that has leaked from small blood vessels into the skin and tissues after a knock. Platelets plug the leak and clotting proteins seal it. You bruise more easily when:

• vessels are fragile or poorly supported by skin and connective tissue
• platelets are too few or do not work well
• clotting factors are missing or blocked by medicine

Bruises change color as the blood breaks down: red-purple, then blue, green, yellow and brown over 1 to 2 weeks.

Common causes of easy bruising

Age and sun damage

With age, skin thins and loses the fat and collagen that cushion blood vessels. Years of sun exposure weaken vessel walls further. The result is senile (actinic) purpura: flat, dark purple patches on the backs of the hands and forearms after trivial bumps. They are harmless, though they take weeks to fade.

Medicines and supplements

• aspirin and NSAIDs such as ibuprofen and naproxen, which reduce platelet function
• anticoagulants such as warfarin, apixaban and rivaroxaban, and antiplatelet drugs such as clopidogrel
• corticosteroids, including long-term inhaled steroids and steroid creams, which thin skin
• SSRI antidepressants, especially combined with aspirin or NSAIDs
• fish oil, ginkgo, vitamin E, garlic and turmeric supplements in high doses

Never stop a prescribed blood thinner yourself. Talk to your doctor.

Easy bruising in women

Women bruise more readily than men, partly because of thinner skin and the way fat is distributed in the thighs and upper arms. But easy bruising plus heavy periods (soaking a pad or tampon every hour or two, or periods lasting more than 7 days) is a classic sign of von Willebrand disease, the most common inherited bleeding disorder. It is underdiagnosed in women.

Medical causes

Low or dysfunctional platelets

• Immune thrombocytopenic purpura (ITP): the immune system destroys platelets. Bruises appear with petechiae (pinpoint red spots), often after a viral infection in children.
• Thrombocytopenia from other causes: medicines, heavy alcohol use, an enlarged spleen, pregnancy, bone marrow problems.
• Inherited platelet function disorders.

Clotting factor problems

• Hemophilia A and B, mostly in males, with deep bruises and bleeding into joints.
• Von Willebrand disease, with bruising, nosebleeds, gum bleeding and heavy periods.
• Liver disease, because the liver makes most clotting factors.
• Vitamin K deficiency, from malabsorption, long antibiotic courses or poor diet.

Blood cancers and marrow problems

Leukemia and other marrow disorders crowd out platelet production. Bruising comes with tiredness, pale skin, infections, fevers, bone pain or night sweats.

Connective tissue and vessel problems

• Ehlers-Danlos syndrome: fragile skin, hypermobile joints, wide scars and easy bruising.
• Cushing syndrome: thin skin and bruising from excess cortisol.
• Scurvy: severe vitamin C deficiency causes bruising, bleeding gums and spots around hair follicles.
• Vasculitis: raised purple spots, often on the legs.

Bruises that are not explained by the story

Unexplained bruises in children, older adults or partners, especially on the face, ears, neck, torso, buttocks or in patterns (fingertip marks, loops), can be a sign of abuse. Health professionals are trained to ask about this sensitively.

Which pattern points where

How easy bruising is investigated

Your doctor will ask about the bruising pattern, other bleeding (nosebleeds, gums, periods, after dental work, surgery or childbirth), medicines and supplements, alcohol, and family history. A bleeding questionnaire may be used.

Initial blood tests:

• complete blood count including platelets and a blood film
• PT/INR and aPTT, which screen the clotting pathways
• fibrinogen and liver function
• von Willebrand factor tests and factor VIII levels if history suggests an inherited disorder

Normal screening tests do not completely rule out von Willebrand disease or a platelet function disorder, so referral to a hematologist is common when the history is strong.

Treatment and self-care

• Treat the cause: adjust medicines, treat ITP, replace clotting factors, correct vitamin deficiencies, manage liver disease.
• For a fresh bruise: apply a cold pack wrapped in a cloth for 15 to 20 minutes, a few times in the first day, and raise the area.
• Use acetaminophen (paracetamol) for pain rather than aspirin or ibuprofen if you bruise easily, unless your doctor advises otherwise.
• Protect fragile skin: long sleeves, padding on furniture edges, good lighting to prevent knocks, and daily sunscreen.
• Keep a photo diary of unexplained bruises to show your doctor.

Frequently asked questions

Why do I bruise so easily all of a sudden?

A sudden change is often due to a new medicine or supplement, such as aspirin, ibuprofen, blood thinners, steroids or fish oil. If there is no obvious cause, or you also have nosebleeds, gum bleeding, tiny red spots or tiredness, get a blood test to check your platelets and clotting.

Is easy bruising a sign of leukemia?

It can be, but it is rarely the only sign. Leukemia usually causes bruising together with tiredness, pale skin, frequent infections, fevers, night sweats or bone pain. A simple blood count will usually show abnormalities if leukemia is the cause.

What vitamin deficiency causes easy bruising?

Vitamin C deficiency (scurvy) and vitamin K deficiency can both cause easy bruising. Vitamin K deficiency is more common in people with malabsorption, liver disease or on long antibiotic courses. A blood test can check, so avoid high-dose supplements without advice.

Why do women bruise more easily than men?

Women tend to have thinner skin and less supportive connective tissue around small vessels, especially on the thighs and upper arms. However, easy bruising with heavy periods can signal von Willebrand disease and should be investigated.

When should I see a doctor about bruises?

See a doctor if bruises appear without a cause, are large or frequent, come with other bleeding, appear on the trunk, face or back, or come with fatigue, fever or weight loss. Seek emergency care for widespread spots with fever or uncontrollable bleeding.