What causes cloudy urine?

Urine may look hazy after you have not had enough fluid, because it becomes more concentrated. Crystals or other minerals can also change its appearance. A sample may be contaminated by mucus or discharge from the genital area, especially when there are no urinary symptoms.

A urinary tract infection can make urine cloudy because white blood cells, bacteria and inflammatory material enter the urine. Burning when passing urine, needing to pass urine often, lower abdominal discomfort or an unusual smell can support this possibility. A kidney infection may cause cloudy urine together with fever, chills, nausea or pain in the side or back.

Notice whether the change settles after drinking fluids normally and whether it happens again. Do not force large amounts of water if you have been told to restrict fluids. Record associated symptoms, recent medicines and whether the sample was collected during vaginal bleeding or discharge.

A clinician may examine a urine sample to look for infection, blood, protein or crystals. Treatment depends on the finding; antibiotics are used only when a bacterial infection is diagnosed or strongly suspected. Explore [Cloudy Urine](/symptoms/cloudy-urine/) for symptom details and [Dehydration](/conditions/dehydration/) for fluid-loss clues.

Arrange medical advice if cloudy urine persists, keeps returning, or comes with burning, urgency, blood, lower abdominal pain or difficulty passing urine. Seek urgent care for fever with side or back pain, vomiting, confusion, severe weakness or feeling rapidly worse, as these can occur with a kidney infection. See [Urinary Tract Infection](/conditions/urinary-tract-infection/) and [Kidney Infection](/conditions/kidney-infection/) for related symptoms.

Ask whether you need a urine test, whether your medicines or fluid intake could explain the change, and which symptoms should prompt same-day review. Mention pregnancy, recurrent infections, kidney problems, fever, pain or visible blood.