Bloody Urine – Causes of Red Color, Blood in Urine

Urine with a reddish color does not always indicate the presence of blood or bleeding within the urinary tract. Similarly, the presence of blood in the urine may not be visible to the naked eye. In order to differentiate between reddish brown discoloration of urine and bloody urine, it is important to test for the presence of red blood cells.

Red blood cells in the urine is  a clear indication of bleeding, usually within the urinary tract. The bleeding may stem from the kidneys, ureter, bladder, prostate (males) or urethra. The presence of red blood cells in the urine is known by the medical term, hematuria (hema ~ blood, uria ~ in urine). Hematuria is not always a cause for concern and may resolves spontaneously with no treatment. However persistent blood in the urine usually indicates a more serious problem that requires further investigation and the appropriate treatment.

Causes of Hematuria, Blood or Red Color of Urine

The causes of hematuria usually involves the urinary tract or related structures in the pelvis and perineum. However red urine may result due to a wide range of causes that is not isolated to the genitourinary system.

Red Discoloration

  • Foods and drinks. Beets, some berries, rhubarb, some sports and energy drinks.
  • Drugs. Certain medication may cause a red to reddish brown discoloration of the urine including some anti-hypertensives (for high blood pressure), anticoagulants (‘blood thinning’ agents), NSAIDS like aspirin, antibiotics (specifically penicillin), antihistamines (for allergies), antipsychotics (for schizophrenia and other psychosis) and antiepileptic medication. It is important to note reddish discoloration of urine will not occur in all medication used to treat these conditions and is dependent on the active ingredient used in the drug.
  • Herbal remedies, especially those used to treat constipation or for ‘bowel cleansing’ and ‘detoxification’.
  • Paint and heavy metals. Lead based paints. Mercury poisoning.
  • Vitamin and mineral supplements. High doses of multivitamins or individual vitamins and minerals may cause an dark yellow to orange red appearance to urine.
  • Porphyria


  • Urinary tract infection. This is the most common cause of blood in the urine. Blood may not be visible in acute urinary tract infections but in chronic or persistent UTI’s, there is noticeable change in the color of the urine. Other symptoms of a UTI include frequent urination; constant urging; burning on urination and/or itching. A fever may be present and a UTI may be a cause of bedwetting in children. Urinary tract infections affect any part of the genitourinary tract but bladder infections (cystitis) are the most common type of UTI.
  • Kidney stones. Other symptoms of kidney stones include severe pain usually aggravated when urinating; constant ache and pain in the abdomen especially around the area of the kidneys; nausea and/or vomiting. The pain and bleeding may increase as the stone passes through the urinary tract (urinary calculi).
  • Renal failure and other kidney disorders. Other symptoms that may be noticed include edema (body swelling), especially swelling of the legs; high blood pressure; fatigue and dizziness.
  • Trauma to the abdomen and/or pelvis  may cause blood in the urine. This is also noticed in sportspersons and may be due to overexertion, dehydration as well as injuries sustained during activities.
  • Prostate disorders like prostatitis (infections) and benign prostatic hyperplasia (BPH) or enlarged prostate which often occurs in older men.
  • Menstrual/gynecological disorders. Conditions causing irregular or heavy menses which results in menstrual blood mixing with urine.
  • Cancer of the kidney, ureter, prostate or bladder may cause hematuria.

Other less common causes include schistosomiasis (bilharzia), sickle cell disease, sexually transmitted diseases (STD’s), malaria, injury to the gentials and bleeding disorders like hemophilia.

Painless Hematuria

Pain may not always be a presenting feature although other urinary symptoms may be evident.

Some of the causes of painless hematuria include :

Kidney disease

A number of kidney disorders may result in painless hematuria. In severe cases or as the condition progresses, pain may become a feature.

  • Acute tubular necrosis
  • Glomerulonephritis
  • Hypertensive nephrosclerosis
  • Interstitial nephritis
  • Polycystic kidney disease
  • Renal ischaemia


Any tumor within the urinary tract may result in hematuria. This includes a tumor in the kidney, ureter or bladder. Prostate tumors may also be responsible for blood in the urine although there is usually some pain by the time hematuria becomes obvious.


Urinary tract infections (UTI’s) may be painless in the early stages but often results in pain. Other infections like tuberculosis and schistosomiasis may result in painless hematuria.


  • Extreme physical activity or exercise as seen in long distance runners (runner’s hematuria)
  • Bleeding disorders
  • Kidney stones without obstruction

Diagnosis (Investigation/Tests)

In most cases, a medical doctor will initially conduct a urine dipstick test to confirm the presence of red blood cells in the urine. Upon confirming hematuria, further investigation is required to identify the cause of the blood in the urine. A urinalysis may be conducted to identify the presence of white blood cells, protein, deformed red blood cells or microorganisms in the urine. A urine culture may be undertaken to identify the causative organism, specifically bacterial species. A urea and electrolyte test may be conducted to verify the functioning of the kidneys and an ultrasound or CT scan may be necessary to identify other conditions.

The incidence of prostate cancer  means that further testing like blood tests for PSA (prostate-specific antigen) and a prostate biopsy may be necessary in high risk individuals. These test may be conducted in men over 50 years of age with persistent hematuria, difficult and painful urination and hard spots on the prostate (detected upon digital rectal examination).

Treatment of blood in the urine  is directed at the causative factor or condition after confirming the diagnosis.


  1. Urine Color. Mayo Clinic
  2. Causes of Hematuria. Wrong Diagnosis
  3. Urine bloody. Medline Plus

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