Common causes of cloudy urine

Cloudy urine is often nothing to be overly concerned about. But you should let your doctor know about it if it persists, especially if you have other symptoms. Here's a closer look at what it could mean, and what to do about it.

What should urine look like, and what do we mean by "cloudy" urine?

Cloudy urine looks, well, cloudy. "Normal urine should be transparent and light yellow," explains Dr. Robert Shmerling, Senior Faculty Editor at Harvard Health Publishing. Cloudy urine looks milky or hazy. "If you poured it into a glass, you wouldn't be able to easily see through it."

Common causes of cloudy urine

Here are some reasons why you may notice cloudy urine:

Low acid. Urine is made up of water, salt, and waste products. Normally, these components combine to create urine that ranges from a slightly acidic pH level to slightly alkaline. But in some circumstances, such as persitent vomiting or eating certain foods, your urine can become more alkaline than usual, says Dr. Shmerling. And the more alkaline the urine, the cloudier it appears. "We do sometimes see cloudy urine among vegans, since a diet high in fruits and vegetables raises your urine's pH level," he explains.

Urinary tract infection (UTI). If you have a UTI, white blood cells and even small amounts of blood may appear in your urine and cause it to look cloudy, says Dr. Shmerling. If it is a UTI, you'll usually have other symptoms like painful and frequent urination.

Dehydration. "If your urine is very concentrated, it may appear cloudy because it's dark yellow or, if you're really dehydrated, almost orange," explains Dr. Shmerling.

Diabetes. If your diabetes is not well controlled, sugar can build up in your urine and make it appear cloudy.

Sexually transmitted diseases. STDs like trichomoniasis, gonorrhea, or chlamydia can cause cloudy urine in men or women.

Certain medications. Blood thinners such as warfarin have been linked to blood in the urine, which can make it look cloudy. Certain medications, such the antibiotic rifampin, can cause the color of urine to change, giving it a cloudy appearance, notes Dr. Shmerling.

Kidney disease. Cloudy urine can sometimes be a sign of kidney disease, especially if it's accompanied by small foamy bubbles. It can also indicate kidney stones, although kidney stones usually cause additional symptoms like abdominal or flank pain and vomiting.

Prostate problems. "If you have a prostate infection, white blood cells can build up in your urine," explains Dr. Shmerling. If your prostate is inflamed, that can cause problems too. "It can damage the urethra, the tube that allows urine to leave your body," he says. "If it's injured, blood and other debris can enter urine and make it look cloudy."

When to see a doctor for cloudy urine

If you notice cloudy urine but otherwise feel fine, there's no need to be overly concerned, says Dr. Shmerling. Since it could be caused by dehydration, make sure to drink plenty of liquids.

But if cloudy urine lasts more than 24 hours, or it goes away only to come back, call your doctor. They can run a urine culture and blood tests to try to pinpoint an underlying cause, like a UTI or diabetes.

There are also some situations where you should contact your doctor right away, stresses Dr. Shmerling. These include:

• severe or persistent pain when you urinate
• blood in your urine
• fever
• abdominal or flank pain (this could indicate a kidney stone).