What's a Urine Culture?

Medically Reviewed by Nayana Ambardekar, MD on March 10, 2024
3 min read

Your doctor tells you they want to do a urine culture. It’s a test to check for germs or bacteria in your pee that can cause a urinary tract infection (UTI).

Your urinary tract includes the kidneys, bladder, and the tubes that carry your pee (ureters and the urethra).

An infection usually starts in the bladder or urethra (the tube your pee comes out of). But it can affect any part of this system.

If you have an infection, there may be a burning feeling when you pee. Or, you may feel like you need to go, but nothing or very little comes out. If you also have a fever or belly pain, it may mean you have a more serious infection.

You pee in a cup. It sounds simple enough, and it is. Just make sure you get a “clean” urine sample so any germs found in it are from an infection in your urinary tract and not another source, like your skin.

Here’s how you do it:

  1. Wash your hands.
  2. Wipe the area around where you pee with the cleaning pad given to you. If you’re a woman, spread the outer lips of your vagina and clean from front to back. Men should wipe the tip of their penis.
  3. Pee a little in the toilet first and stop. Don’t pee in the cup right away. Then, collect about 1 or 2 ounces in the cup. Make sure the container doesn’t touch your skin. Finish peeing in the toilet. This is called a “midstream” urine catch.
  4. Wash your hands again.

Some people may need their sample collected through a catheter -- a thin tube put into your urethra and into the bladder. This is done with the help of a health care worker. The sample is placed in a clean container.

Your sample goes to a lab. Drops of your pee are put in a petri dish and stored at body temperature. Over the next few days, any bacteria or yeast in the sample will multiply and grow.

A lab worker will look at the germs under the microscope. Their size, shape, and color tell which types are there. The lab worker will note how many are growing. If it is a true infection, usually one type of bacteria dominates. The lab worker will report the identity of the germ.

If there are no harmful germs, the culture is called “negative.” If there are bad germs growing, it’s “positive.” The most common thing that causes UTIs is E-coli – bacteria that live in your intestines.

The lab may do more testing to see which drugs have the best chance of fighting the infection.

Your doctor’s office will call in 1 to 3 days. They’ll go over the results with you.

If you have an infection, you’ll likely be given antibiotics. If you are, be sure to complete the entire amount prescribed. Most of the time, the infection goes away. But it may come back, especially if you’re a sexually active woman. In young women, sexual intercourse increases the risk for an infection. In older women, being post menopausal and estrogen deficiency increases the risk. The risk is higher in older men who have an enlarged prostate.

It’s important to take your medicine the way your doctor tells you to. An infection that starts in the bladder or urethra can spread to the kidneys and damage them.