The kidneys are a pair of organs in the back of the abdomen that help filter out water-soluble toxins from the blood. Like other parts of the body, kidneys are subject to injury from trauma. One type of injury is a bruise, also known as a hematoma.

Hematomas

Hematomas result from the release of blood into the tissues without necessarily causing bleeding. They are an indicator of trauma since most tissues do not normally bleed easily.

Kidney Damage

The kidneys are positioned in the back of the abdomen, under the last set of ribs. Though the ribs protect them, the kidneys may be injured through trauma from impact, from mechanical shock (like that experienced in an accident), or from poisoning that destroys kidney tissue.

Bruising

Extracorporeal shockwave lithotripsy (ESWL) is the use of high-frequency sound waves to break up kidneys stones so they may pass more easily through the urinary tract. Kidney bruising may happen as a complication of ESWL since the sound waves may bruise thicker kidney tissues.

Trauma

Even with the protection of the ribs, a direct hit on the area of the kidneys may actually push the ribs into the kidney or kidneys, bruising them. Trauma from the front of the body may also bruise the kidneys by pushing the kidneys into the ribs.

Symptoms

Hematuria (urine in the blood) is one sign of kidney damage, including bruising, after abdominal trauma. The kidneys may also become inflamed, decreasing their ability to filter blood and produce urine.

Source:

Renal Trauma

Surgery: Renal Trauma

Renal Hematoma as a Complication of Extracorporeal Shock Wave Lithotripsy