Bruised kidney
Key points
- An upper urinary tract injury is one sustained by the kidneys and ureters.
- The kidneys are located in the flank (back of the upper abdomen at either side of the spinal column).
- A history of physical injury, exposure to potentially toxic substances, or recent infections or illness may indicate the source of injury to the kidney.
- Treatment goals include treatment of emergency symptoms and prevention or treatment of complications.
Alternative names
Kidney damage; Toxic injury of the kidney; Kidney injury; Traumatic injury of the kidney; Fractured kidney; Inflammatory injury of the kidney; Ureteral injury
Definition
An upper urinary tract injury is one sustained by the kidneys and ureters.
Causes, incidence, and risk factors
The kidneys are located in the flank (back of the upper abdomen at either side of the spinal column). They are deep within the abdomen and are protected by the spine, lower rib cage, and the strong muscles of the back.
This location protects the kidneys from many external forces. They are well-padded for a reason - kidneys are highly vascular organs, which means that they have a large blood supply. If injury occurs, severe bleeding may result.
Kidneys may be injured by damage to the blood vessels that supply or drain them. This may be in the form of aneurysm, arteriovenous fistula, arterial blockage, or renal vein thrombosis.
The extent of bleeding depends on the location and the degree of injury. Kidneys may also bleed profusely if they are damaged centrally (on the inside) - this is a life-threatening injury. Fortunately, most kidney injuries caused by blunt trauma occur periperally, only causing bruising of the kidney (usually a self-limiting process).
People with undiagnosed kidney conditions - such as anigomyolipoma (benign tumor), ureteropelvic junction obstruction (congential or acquired UPJ Obstruction), and other disorders - are more susceptible to kidney injuries and more likely to have serious complications if they occur.
Other causes of kidney injury and bleeding are medical procedures. Kidney biopsies, nephrostomy tube placements, or other surgeries can cause an abnormal connection between an artery and vein (arteriovenous fistula). This is usually a self-limiting problem, but close observation is usually needed.
Injury to the kidney can also disrupt the urinary tract, causing leakage of the urine from the kidney.
Each kidney filters about 1700 liters of blood per day and concentrates fluid and waste products into about 1 liter of urine per day. Because of this, the kidneys receive more exposure to toxic substances in the body than almost any other organ. Therefore, they are highly susceptible to injury from toxic substances.
Analgesic nephropathy is one of the most common types of toxic damage to the kidney. Exposure to lead, cleaning products, solvents, fuels, or other nephrotoxic chemicals (those which can be toxic to the kidney) can damage kidneys.
Excessive buildup of body waste products, such as uric acid (that can occur with gout or with treatment of bone marrow, lymph node, or other disorders) can also damage the kidneys.
Written and revised by
Andrey Nailor, M.D.
Our doctors write and review articles for accuracy and keep them up to date.
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