Almost anyone — including children and teens — can have red blood cells in the urine. Factors that make this more likely include:

  • Age. Many men older than 50 have occasional hematuria due to an enlarged prostate gland.
  • Your sex. More than half of all women will have a urinary tract infection at least once in their lives, possibly with some urinary bleeding. Younger men are more likely to have kidney stones or Alport syndrome, a form of hereditary nephritis that can cause blood in the urine.
  • A recent infection. Kidney inflammation after a viral or bacterial infection (post-infectious glomerulonephritis) is one of the leading causes of visible urinary blood in children.
  • Family history. You may be more prone to urinary bleeding if you have a family history of kidney disease or kidney stones.
  • Certain medications. Aspirin, nonsteroidal anti-inflammatory pain relievers, and antibiotics such as penicillin are known to increase the risk of urinary bleeding.
  • Strenuous exercise. Long-distance runners are especially prone to exercise-induced urinary bleeding. In fact, the condition is sometimes called jogger's hematuria. But anyone who works out strenuously can develop symptoms.
Sep. 01, 2011