The list of causes of blood in the urine (called hematuria
) is long and varied. The kidney is one potential source of the problem. Problems within the kidney that can cause hematuria include a kidney stone (irritating the lining of the kidney), an infection, a ruptured cyst, and inflammation of the kidney cells from any of a number of causes (i.e., glomerulonephritis). Cancer is always something to consider if hematuria persists and another cause is not discovered, and can develop anywhere among the kidneys, ureters, prostate and bladder.
Kidney stones trapped within the ureters (the tubes connecting the kidney to the bladder) can also cause hematuria. Inflammation of the bladder (cystitis), bladder stones, and lower urinary tract infections (UTIs) can also cause hematuria. Sexually transmitted diseases could also cause hematuria, though isolated hematuria without other symptoms such as penile discharge and burning would be uncommon.
If your husband has not had his urine analyzed yet, this would be the recommended first step, as not all dark urine is due to blood. For example, an elevated bilirubin level in the blood can cause the urine to appear dark. Your husband should talk to his primary care physician
about his urinary symptoms.