Weak positive urine occult blood indicates that in routine urine examination, some microscopic hematuria may exist and urine occult blood may be positive, sometimes accompanied by proteinuria, tubular urine, or urine occult blood alone, but the common reasons are as follows: 1. Physiological factors, including before and after menstruation, can appear weak positive urine occult blood. 2. Infectious diseases, such as urinary tract infection, manifested as hemorrhagic cystitis, can have weak positive urinary occult blood in a short time after treatment. 3. Renal calculi, renal tumors, sometimes urine occult blood continued positive, but often combined with obvious gross hematuria. 4. Weak positive urine occult blood can also occur after various glomerular diseases, such as glomerulonephritis, lupus nephritis, purpura nephritis, etc.
