Patient information: Blood in the urine (hematuria) in adults

BLOOD IN THE URINE OVERVIEW

Hematuria is the medical term for red blood cells in the urine. Red blood cells in the urine can come from the kidney (where urine is made) or anywhere in the urinary tract (figure 1). The urinary tract includes the ureters (the tubes from the kidneys to the bladder), the bladder (where urine is stored), and the urethra (the tube through which urine exits the body).

Although seeing blood in the urine can be frightening, most of the time hematuria is not life threatening. However, it is important to investigate the cause of hematuria because rarely, it is caused by a serious condition.

This article will review the potential causes, evaluation, and treatment of blood in the urine in adults. Blood in the urine in children is discussed separately. (See "Patient information: Blood in the urine (hematuria) in children".) More detailed information is available by subscription. (See "Evaluation of hematuria in adults".)

TYPES OF HEMATURIA

There are two main types of hematuria: gross and microscopic.

• Gross hematuria — Gross hematuria means that you can see blood with the naked eye because the is urine pink, red, brownish-red, or tea-colored. If you see blood in your urine, you should call your healthcare provider.
• Microscopic hematuria — Microscopic hematuria means that the urine is normal in color, but there are an increased number of red blood cells seen with a microscope. It is usually discovered when a urine sample is tested with a dipstick. The results of a dipstick test should be confirmed with a microscopic examination.

CAUSES OF BLOOD IN THE URINE

A number of conditions can cause hematuria.

• Bladder infection (also called acute cystitis), which typically causes burning or pain with urination, (see "Patient information: Bladder infections in adolescents and adults")

• Kidney infection (also called pyelonephritis) (see "Patient information: Kidney infection (pyelonephritis)")

• Kidney stones, which usually present with one-sided back pain that can be severe (see "Patient information: Kidney stones in adults")

• Certain kidney diseases
• Vigorous exercise or injury (for example, after falling off a bike and bruising a kidney)
• Enlargement of the prostate (called benign prostatic hyperplasia), which is a common problem in older men
• Cancer of the bladder, prostate, or kidney, usually in patients over age 50 (see "Patient information: Bladder cancer diagnosis and staging".

Sometimes, the urine appears to have blood in it because there are other red substances (pigments) in the urine. This can happen if you eat an excessive amount of beets (called beeturia), food dyes, or certain medications (such as phenazopyridine/Pyridium®).

EVALUATION OF BLOOD IN THE URINE

There are a number of tests available to determine the cause of hematuria. Most people do not need every single test.

• Urine tests — Urine tests can provide clues about the cause of hematuria. This may include a urine cytology, which uses a microscope to analyze cells from the lining of the bladder and kidney (found in the urine).
• Blood tests — Blood tests may be used to look for evidence of kidney or other diseases that can cause hematuria.
• CT scan — Computed tomography, or CT scan, is a radiologic test that examines the structure of the kidneys, ureters, and bladder. Kidney stones or abnormalities of the kidneys, ureters, and bladder can usually be seen with a CT scan. A dye is usually injected into a vein during the test, which highlights any possible abnormalities.
• Kidney ultrasound — Ultrasonography of the kidney is an alternative to CT scan, and is preferred for people who are allergic to the dye used in CT. Ultrasound uses sound waves to create a picture of the kidney's structure.
• Cystoscopy — Cystoscopy is a procedure that may be done in an office setting or as a day surgery procedure. A small tube with a camera is inserted into the bladder through the urethra (figure 1). A numbing gel is applied before the tube is inserted to decrease discomfort.

During cystoscopy, the physician examines the lining of the bladder to determine if there are any abnormalities. If abnormal tissue is seen, a biopsy can be taken. The biopsy is examined with a microscope to determine if abnormal or cancerous cells are present.

• Kidney biopsy — During a kidney (renal) biopsy, a clinician removes a small piece of tissue from the kidney; the tissue is later examined with a microscope for signs of kidney disease. A full description of renal biopsy is available separately. (See "Patient information: Renal (kidney) biopsy".)

TREATMENT OF BLOOD IN THE URINE

There is no specific treatment for hematuria. Rather, treatment is aimed at the underlying cause, if a cause can be determined. (See "Patient information: Bladder infections in adolescents and adults" and "Patient information: Kidney stones in adults" and "Patient information: Glomerular disease overview" and "Patient information: Chronic kidney disease".)

Follow up testing — If no underlying cause for hematuria is found during the initial evaluation, follow up urine testing and blood pressure monitoring may be recommended every 3 to 6 months.

This is especially true if you are at increased risk for bladder cancer. A number of factors can increase your risk of bladder cancer, including being older than 50 years, smoking cigarettes, and exposure to certain industrial chemicals. (See "Patient information: Bladder cancer diagnosis and staging".)

WHERE TO GET MORE INFORMATION

Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two people are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.

This discussion will be updated as needed every four months on our web site (www.uptodate.com/patients). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.

Some of the most pertinent include:

Patient Level Information:
Patient information: Kidney stones in adults
Patient information: Blood in the urine (hematuria) in children
Patient information: Bladder infections in adolescents and adults
Patient information: Kidney infection (pyelonephritis)
Patient information: Bladder cancer diagnosis and staging
Patient information: Renal (kidney) biopsy
Patient information: Glomerular disease overview
Patient information: Chronic kidney disease

Professional Level Information:
Acute cystitis and asymptomatic bacteriuria in men
Acute cystitis in women
Evaluation of hematuria in adults
Exercise-induced hematuria
Glomerular hematuria: IgA; Alport; thin basement membrane nephropathy
Hematuria following an upper respiratory infection
Hematuria: Glomerular versus extraglomerular bleeding
Indications for and complications of renal biopsy
Loin pain-hematuria syndrome
Red to brown urine: Hematuria; hemoglobinuria; myoglobinuria
Thin basement membrane nephropathy (benign familial hematuria)
Urinalysis in the diagnosis of renal disease

A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable.

• National Library of Medicine

      (www.nlm.nih.gov/medlineplus/healthtopics.html)

• National Institute of Diabetes and Digestive and Kidney Diseases

      (www.niddk.nih.gov)

• National Kidney Foundation

      (www.kidney.org)

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