Hematuria (Blood in Urine)
Blood in the urine, whether visible or seen only on testing
Quick Facts
- Type: Urinary symptom
- Common causes: Infection, kidney stones, enlarged prostate
- Types: Visible (gross) and microscopic
- Seek urgent care: Inability to urinate, clots, severe pain, fever
Overview
Hematuria is the medical term for blood in the urine. It is divided into two kinds. Gross (visible) hematuria turns the urine pink, red, or cola-colored and is noticed by the person. Microscopic hematuria means blood cells are present but in amounts too small to change the urine's color, so it is found only on a urine test, often during a routine check.
Even a small amount of blood can dramatically change the color of urine, so visible bleeding does not always mean a large blood loss. Hematuria itself is a sign rather than a disease; it can come from anywhere along the urinary tract, including the kidneys, ureters, bladder, prostate, or urethra. Because some causes are serious, new blood in the urine should always be checked by a doctor, even if it appears only once and then stops.
Common Causes
Blood in the urine can arise anywhere in the urinary system, from the kidneys down to the urethra.
- Urinary tract infection: Bladder or kidney infections can irritate the lining and cause bleeding, often with burning and frequent urination.
- Kidney stones: Stones can scratch the urinary tract as they move, causing pain and blood.
- Enlarged prostate: In older men, a benign enlarged prostate can lead to blood in the urine.
- Kidney disease: Inflammation of the kidney's filters can let blood into the urine.
- Vigorous exercise: Strenuous activity sometimes causes temporary, harmless hematuria.
- Tumors: Bladder or kidney cancer can cause painless visible bleeding, which is why hematuria must always be evaluated.
- Medications: Blood thinners and some other drugs can contribute.
Beet, blackberry, and certain food dyes, as well as some medicines, can color urine red without any blood being present.
Associated Symptoms
Symptoms accompanying hematuria help reveal where the bleeding comes from and how urgent it is.
- Burning or pain during urination (suggesting infection)
- Frequent or urgent need to urinate
- Flank or back pain, often with kidney stones or infection
- Lower abdominal or pelvic discomfort
- Fever and chills (suggesting infection that may involve the kidney)
- Difficulty starting urination or a weak stream (in prostate enlargement)
- Blood clots in the urine or difficulty passing urine
Painless visible blood in the urine, with no other symptoms, still needs evaluation because it can be the only early sign of a bladder or kidney tumor.
Diagnosis & Evaluation
The goal of evaluation is to confirm true hematuria and find its source. A clinician reviews symptoms, medications, and risk factors, then orders tests as needed.
- Urinalysis: Confirms blood and checks for infection or protein.
- Urine culture: Identifies a urinary infection.
- Imaging: Ultrasound or CT scans look for stones, tumors, or kidney problems.
- Cystoscopy: A thin camera passed into the bladder to inspect the bladder and urethra directly, especially when cancer is a concern.
- Blood tests: Assess kidney function.
The extent of testing depends on age, risk factors such as smoking, and whether the bleeding is visible or microscopic.
Treatment & Management
Treatment depends on the underlying cause rather than the bleeding itself.
- Infection: Treated with antibiotics, after which the blood usually clears.
- Kidney stones: Managed with fluids, pain relief, and sometimes procedures to remove the stone.
- Enlarged prostate: Treated with medication or, in some cases, a procedure.
- Kidney disease: Managed by a specialist, sometimes with medicines to control inflammation or blood pressure.
- Tumors: Require specialist care, which may include surgery or other cancer treatments.
If a medication is responsible, a doctor may adjust it. When no serious cause is found, follow-up testing may be recommended to be sure the hematuria does not return or signal a developing problem.
When to See a Doctor
Always contact a doctor when you notice blood in your urine, even once. Seek urgent or emergency care if you have:
- Inability to urinate or blood clots blocking the flow of urine
- Heavy, ongoing visible bleeding
- Severe flank or abdominal pain
- Fever and chills with blood in the urine
- Dizziness, weakness, or a racing heart
Do not assume visible blood is harmless just because it is painless. Painless hematuria can be the first sign of a serious condition and must be evaluated promptly.
Frequently Asked Questions
Does blood in the urine always mean something serious?
Not always. Common causes such as urinary tract infections, kidney stones, and an enlarged prostate are not cancer. However, because hematuria can occasionally be the first sign of a bladder or kidney tumor, any blood in the urine should be evaluated by a doctor.
Why is my urine red if there is no blood in it?
Some foods such as beets and blackberries, certain food dyes, and some medications can turn urine red, pink, or orange without any blood. A urine test can tell whether the color is from actual blood. If you are unsure, it is safest to have it checked.
Is painless blood in the urine less worrying?
No. Painless visible blood in the urine can actually be the only early warning sign of a bladder or kidney tumor, so it should never be ignored. Whether or not it hurts, new blood in the urine needs medical evaluation.
Can exercise cause blood in the urine?
Yes. Strenuous exercise, especially long-distance running, can cause temporary, usually harmless blood in the urine. It typically clears within a day or two of rest. Even so, if it persists or recurs, see a doctor to rule out other causes.
When is blood in the urine an emergency?
Seek emergency care if you cannot urinate, are passing large blood clots, have severe pain, develop fever and chills, or feel faint and weak. These can signal a blockage, infection involving the kidney, or significant blood loss.
References
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Hematuria (Blood in the Urine).
- Mayo Clinic. Blood in urine (hematuria) — Symptoms and causes.
- American Urological Association. Microhematuria.
- MedlinePlus, U.S. National Library of Medicine. Urine - bloody.