Urinary Tract Infection (UTI): This is often the most common cause of acute hematuria, especially in women. Bacteria can cause inflammation and irritation in the urinary tract, leading to bleeding.

Kidney Stones: Stones can cause bleeding by irritating the urinary tract or by causing a blockage that leads to increased pressure and subsequent bleeding.
Bladder or Kidney Trauma: Any form of injury to the urinary tract can result in blood in the urine.
Prostate Issues (in men): Conditions like prostatitis or benign prostatic hyperplasia (BPH) can cause hematuria due to the proximity of the prostate to the urinary tract.

Cancer (Bladder, Kidney, or Prostate): Although less common, cancer is a critical diagnosis that must not be missed. Hematuria can be an early sign of these cancers.
Vasculitis or Glomerulonephritis: These are inflammatory conditions that affect the blood vessels in the kidneys or the kidneys themselves, which can lead to hematuria and are potentially serious if not treated promptly.
Bleeding Disorders: Conditions like hemophilia or the use of anticoagulant medications can increase the risk of bleeding, including into the urinary tract.

Sickle Cell Disease or Trait: These conditions can cause sickling of red blood cells in the low-oxygen environment of the kidney, leading to damage and potential bleeding.
Arteriovenous Malformation (AVM): A rare condition where there's an abnormal connection between arteries and veins, which can occur in the kidney or bladder and cause bleeding.
Tuberculosis: Although rare in many parts of the world, TB can infect the urinary tract and cause hematuria among other symptoms.
Goodpasture Syndrome: A rare autoimmune disease that can cause bleeding in the lungs and kidneys, leading to hematuria.