This test requires a urine sample. The sample is taken by placing a thin rubber tube (called a catheter) through the urethra into the bladder. A nurse or a trained technician may do this.

First, the area around the opening of the urethra is thoroughly washed with a germ-killing (antiseptic) solution. The tube is inserted into the urethra. The urine drains into a sterile container, and the catheter is removed.

Rarely, your health care provider may choose to collect a urine sample by inserting a needle directly into the bladder from the abdominal wall and draining the urine. However, this is most often done only in infants or to immediately screen for bacterial infection.

The urine is sent to a laboratory. Tests are done to determine if there are germs in the urine sample. Other tests may be done to determine the best medicine to fight the germs.

Do not urinate for at least 1 hour before the test. If you don't have the urge to urinate, you may be instructed to drink a glass of water 15 to 20 minutes before the test. Otherwise, there is no preparation for the test.

There is some discomfort. As the catheter is inserted, you may feel pressure. If you have a urinary tract infection, you may have some pain when the catheter is inserted.

The test is done:

• To get a sterile urine sample in a person who cannot urinate on their own
• If you might have a urinary tract infection
• If you cannot empty your bladder (urinary retention)

Normal values depend on the test being performed. Normal results are reported as "no growth" and are a sign that there is no infection.

A "positive" or abnormal test means germs, such as bacteria or yeast, are found in the urine sample. This likely means that you have a urinary tract infection or a bladder infection. If there is only a small amount of germs and you have no symptoms, your provider may not recommend treatment.

Sometimes, bacteria that do not cause urinary tract infections may be found in the culture. This is called a contaminant. You may not need to be treated.

People who have a urinary catheter all of the time may have bacteria in their urine sample, but it does not cause a true infection. This is called being colonized.

Risks include:

• Perforation (hole) in the urethra or bladder from the catheter
• Infection

Culture - urine - catheterized specimen; Urine culture - catheterization; Catheterized urine specimen culture

Dean AJ, Lee DC. Bedside laboratory and microbiologic procedures. In: Roberts JR, Custalow CB, Thomsen TW, eds. Roberts and Hedges' Clinical Procedures in Emergency Medicine and Acute Care. 7th ed. Philadelphia, PA: Elsevier; 2019:chap 67.

Germann CA. Urologic disorders. In: Walls RM, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 85.

James RE, Fowler GC. Bladder catheterization (and urethral dilation). In: Fowler GC, ed. Pfenninger and Fowler's Procedures for Primary Care. 4th ed. Philadelphia, PA: Elsevier; 2020:chap 96.

Trautner BW, Hooton TM. Health care-associated urinary tract infections. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 302.

Updated by: Linda J. Vorvick, MD, Clinical Professor, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.