A hard bruise is often a hematoma. A hematoma forms when an injury, usually a direct blow, damages blood vessels, causing blood to collect and pool under the skin. This pooled blood clots, creating a firm, lumpy mass that feels hard to the touch. This differs from a typical bruise, which may be tender but generally not as hard. The severity of the injury dictates the size and hardness of the hematoma.
Understanding Hematomas and Hard Bruises
- Mechanism: A hematoma occurs when trauma damages blood vessels, allowing blood to escape into surrounding tissues. This escaped blood forms a localized collection, resulting in a hard lump. [Source: A hematoma or haematoma is where trauma or injury (usually a direct hit) damages your veins or arteries - blood escapes and collects outside the blood vessels (arteries and veins) in a muscle or within soft tissue and can form a localised hard mass under the surface of your skin.]
- Appearance: Hematomas present as a firm, lumpy, or even spongy area under the skin. The hardness is a direct result of the clotted blood. [Source: Many injuries can develop a hematoma and give the area a firm, lumpy appearance. Also: With a hematoma, the leaking blood will pool and clot, or form clumps of blood. This can cause a hard and tender mass.]
- Difference from Bruises: While both hematomas and bruises involve blood leaking from damaged vessels, hematomas involve a larger volume of blood pooling, resulting in a noticeable, hard mass. A simple bruise may appear as discoloration without the same firmness. [Source: A hematoma is a bad bruise. It happens when an injury causes blood to collect and pool under the skin. The pooling blood gives the skin a spongy, rubbery,...]
- Bone Bruises: In some cases, a hard lump might indicate a bone bruise (contusion), which involves damage to the bone's soft tissues. This can also manifest as a hard area, accompanied by pain and swelling. [Source: Symptoms of a bone bruise can include: Pain and tenderness in the injured area; Swelling in the area and soft tissues around it; Hard lump in the area; Change...]
When to Seek Medical Attention
While many hematomas resolve on their own, consult a doctor if:
- The bruise is extremely painful or swollen.
- The area shows signs of infection (increased redness, warmth, pus).
- You experience numbness or tingling in the area.
- The hardness persists for an extended period.
- The injury was caused by a significant impact.
