Patient education: Urine culture (The Basics)

What is a urine culture? — A urine culture is a lab test that checks urine for bacteria and other germs.

For a urine culture, you give a urine sample. The sample is sent to a lab, where they will add a special substance that causes germs to grow. If bacteria or yeast are in your urine, these will show up within a few days.

A urine culture is different from a "urinalysis." A urinalysis is also done on a urine sample, but it is a simpler test. It can show if you have inflammation in your bladder, which can happen with a urinary tract infection ("UTI"). But if you have a UTI, a urinalysis cannot tell what germ is causing it.

Why might I get a urine culture? — Your doctor might order a urine culture:

●To confirm that you have a UTI if you have symptoms of a bladder or kidney infection

●To help decide what kind of antibiotic to prescribe for a UTI, especially if symptoms don't improve or come back

●To check for bacteria in your urine if you are pregnant

●If you are about to have surgery involving your urinary tract

How do I prepare for a urine culture? — You do not have to do anything special to prepare. Your doctor or nurse might tell you to:

●Avoid urinating for an hour or so before the test.

●Drink water shortly before the test to help you urinate.

In some cases, your doctor or nurse will have you collect your urine at home instead of in the office.

How do I collect my urine? — Your doctor or nurse will give you a clean plastic cup to collect your urine. You need to get a "clean catch" sample. To do this:

●Wash your hands with soap and water.

●Clean your genital area by wiping gently from front to back. Your doctor or nurse might give you a special wipe to use for this.

●Let a little bit of urine out into the toilet, then stop mid-stream.

●Hold the cup so it is ready to catch your urine.

●Start urinating again, and catch the urine in the cup. Fill the cup with as much urine as your doctor or nurse told you to collect. Do not to let the cup touch your body or the toilet.

●Finish urinating in the toilet.

●Give the urine sample to your doctor or nurse. They will send it to a lab for testing.

If you cannot collect your urine yourself, your doctor will collect it in another way. This might involve inserting a thin tube called a "catheter" into your urethra (figure 1). A catheter can also be used to get a sample if a baby or young child needs a urine culture.

What do my results mean? — Your doctor or nurse will tell you when to expect your results, and will contact you with the results. Or if you use an online "patient portal," you might get an alert there when your results are ready.

●If your urine culture is "positive," this means that you do have bacteria or other germs in your urine. Your doctor or nurse will talk to you about what to do next. If you have a bacterial infection, your doctor will prescribe an antibiotic based on what type of bacteria was found in your urine.

●If your urine culture is "negative," this means that you do not have bacteria or other germs in your urine. If you have symptoms but your urine culture is negative, your doctor or nurse might want to do other tests to try to figure out the cause.

More on this topic

Patient education: Urinalysis (The Basics)
Patient education: Urinary tract infections in adults (The Basics)
Patient education: Urinary tract infections in children (The Basics)
Patient education: Blood in the urine (hematuria) in adults (The Basics)
Patient education: Asymptomatic bacteriuria (The Basics)

Patient education: Urinary tract infections in adolescents and adults (Beyond the Basics)
Patient education: Urinary tract infections in children (Beyond the Basics)
Patient education: Blood in the urine (hematuria) in adults (Beyond the Basics)