Bruises

A bruise forms when small blood vessels beneath the skin are damaged and leak blood. The skin usually remains unbroken. The medical term for a larger flat bruise is ecchymosis.

Most bruises follow a minor bump, fall, injection, or other pressure on the body. You may not remember the injury, especially when a bruise appears later.

Some people bruise more easily because their skin and blood vessels are fragile. Medicines and health conditions can also affect platelets or clotting proteins, which help stop bleeding. A bruise alone cannot show what caused it.

A new bruise may be red, blue, purple, or dark brown, depending on your skin tone. As the trapped blood breaks down, it may become green, yellow, or lighter brown before fading. Bruise color cannot reliably show exactly when an injury happened.

The area may be:

• Tender or painful when touched
• Mildly swollen
• Firm if blood has collected into a lump
• More noticeable over the next day or two

Very small red, purple, or brown spots are called petechiae. They may look like a rash and usually do not fade when pressed. Larger patches of bleeding under the skin are called purpura. Sudden petechiae or purpura, especially with fever or other bleeding, need prompt medical assessment.

Common causes include bumps, falls, sports injuries, blood tests, injections, and pressure from tight equipment or carrying heavy objects. Strenuous activity can occasionally damage small blood vessels.

Bruising also becomes easier with age. Skin gets thinner, loses some protective fat, and may be weakened by years of sun exposure. Bruises on the forearms and hands are particularly common in older adults.

Medicines can make bruising more likely. These include anticoagulants like warfarin or apixaban, which slow blood clotting, and antiplatelet medicines, which make platelets less sticky. Aspirin, some anti-inflammatory pain medicines, corticosteroids like prednisone or hydrocortisone, and certain supplements may also contribute.

Less common causes include low platelet levels, inherited bleeding disorders, liver disease, nutritional deficiencies, inflammation of blood vessels, and illnesses affecting the blood or bone marrow. These are more likely to cause concern when bruising is new, frequent, widespread, or accompanied by other bleeding.

Bruises may also result from deliberate harm. If another person has injured you or you do not feel safe, consider contacting someone you trust, a local support service, or emergency services.

Seek emergency help for bruising after a major injury, or when it occurs with:

• Bleeding that will not stop with firm pressure
• Fainting, severe weakness, confusion, or difficulty breathing
• A severe or worsening headache after a head injury
• Vomiting blood, coughing blood, or passing black, tar-like stool
• Severe pain, rapidly increasing swelling, numbness, or a pale limb

If you take an anticoagulant, get urgent medical advice after a significant fall or any head injury, even if you initially feel well.

Arrange same-day medical care if you suddenly develop many bruises or pinpoint spots with fever, feel seriously unwell, or have bleeding from your gums, nose, urine, or bowel. Very heavy menstrual bleeding alongside new bruising also needs prompt assessment.

Book a routine appointment if bruises repeatedly appear without a clear reason, are unusually large, are becoming more frequent, or do not begin to improve. You should also make an appointment if close relatives have unusual bleeding or if bruising began after starting a medicine.

A healthcare professional will ask when the bruises started, where they appear, and whether you have nosebleeds, heavy periods, prolonged bleeding, fever, weight loss, or other symptoms. They may ask about recent injuries, alcohol use, family history, and all medicines and supplements you take.

The examination may look at the size and pattern of bruises, the condition of your skin, and signs of bleeding elsewhere.

If testing is needed, it may include a complete blood count to measure blood cells and platelets. Clotting tests check how long your blood takes to form a clot. Liver tests or more specific tests for bleeding disorders may be appropriate depending on your symptoms and history.

For a minor bruise, protect the area and rest it if movement hurts. During the first day or two, apply a cold pack wrapped in cloth for short periods. Do not put ice directly on your skin. Raising a bruised arm or leg may reduce swelling.

Avoid hard massage or attempts to drain the bruise yourself. There is limited evidence that creams make an ordinary bruise disappear quickly.

Ask a pharmacist or healthcare professional which pain medicine is suitable, especially if you bruise easily or take anticoagulants, aspirin, or antiplatelet medicine. Do not stop a prescribed medicine on your own. A clinician can decide whether it needs review or adjustment.

When a health condition is contributing, treatment focuses on that cause rather than the bruise itself.

Small bruises often fade over about two weeks. Large or deep bruises may take several weeks. A bruise on a leg can appear to move downward as blood tracks through tissues under the effect of gravity.

Tenderness and swelling should gradually improve. Seek medical advice if the area becomes increasingly painful, hot, red, or swollen, or if a firm lump remains.

Can I bruise without remembering an injury?

Yes. A minor bump may go unnoticed, and the discoloration may not appear until later. Repeated unexplained bruising should still be discussed at a routine appointment.

Are changing colors normal?

Usually. Color changes happen as the body breaks down and absorbs leaked blood. Color alone cannot accurately date a bruise.

Do blood-thinning medicines cause bruises?

They can make bruises larger or easier to develop. New or increasing bruising may justify a medication review, but do not stop prescribed treatment without medical advice.

Is a bruise the same as a blood clot?

No. A bruise is blood that has leaked into tissue. A clot inside a deep vein may instead cause one-sided leg swelling, warmth, and pain. Those symptoms require urgent medical assessment.