Cloudy urine is often caused by dehydration or a urinary tract infection , but it can also happen with kidney stones, STIs, diabetes, or even a contaminated sample. Common sources note that cloudiness can come from pus, blood, white blood cells, mucus, salts, or concentrated urine.

Common causes

  • Dehydration, which makes urine more concentrated.
  • UTI, which can make urine cloudy and may also cause burning, frequent urination, or bad odor.
  • Kidney stones, which can irritate the urinary tract and sometimes cause cloudy or painful urination.
  • STIs or genital infections, which may add white blood cells or discharge to the urine.
  • Diet, supplements, or alkaline urine, which can sometimes make urine look milky or hazy.

When it matters

A single cloudy pee episode is often not serious, especially if you were dehydrated. It is more concerning if it keeps happening or comes with burning, fever, back pain, blood in the urine, strong odor, or genital discharge.

What to do now

  • Drink water and see whether the urine clears up over the next several hours.
  • Watch for pain, fever, or burning when you pee.
  • Get medical care soon if the cloudiness persists, keeps returning, or happens with blood, fever, or flank pain.

Extra note

If this is for a urine sample, contamination from discharge or collection technique can make the sample look cloudy even when there is no problem.