The term ecchymosis describes a flat, blue or purple patch measuring 1 centimeter (cm) or more in diameter. The name is often used interchangeably with purpura or bruising, though this is somewhat mistaken.

Ecchymosis occurs when blood leaks from a broken capillary into surrounding tissue under the skin. This causes discoloration.

As the tissue heals, the area of ecchymosis may change from purple or blackish blue to yellow or green. Ecchymosis will typically take between 1 and 3 weeks to resolve.

Areas of ecchymosis have a different appearance from bruises or hematomas, which are swollen patches that form when blood collects and clots outside of a blood vessel. Hematomas may appear raised, while patches of ecchymosis are flat.

Bruises are typically caused by an injury, such as a fall or a knock, while ecchymosis is not always a result of trauma. Diseases and other conditions can also cause ecchymosis.

The main symptom of ecchymosis is discolored skin, caused by the bursting of capillaries and leakage of blood beneath the skin. The color of the patch corresponds to how old and severe the injury is.

When the leakage is recent, the area of ecchymosis may appear dark blue, black, or purple, but it will fade to yellow or green over time.

Ecchymosis alone is not typically a cause for concern. Like bruising, it is most common on legs and arms, and it often results from minor injuries sustained, for example, by bumping into furniture. Ecchymosis also frequently appears in areas where the skin is thin, such as the eyelids or lips.

It is common to see ecchymosis and bruising in highly active children and in older adults because the skin thins and the capillary walls grow more fragile with age.

When trauma is not responsible for ecchymosis, it can occur in people of any age.

The following slideshow contains images of ecchymosis: