What should you know about foul cloudy urine?

Urine may look cloudy when it contains concentrated waste, crystals, mucus, blood or inflammatory cells. A strong smell can follow dehydration, certain foods or medicines, or bacterial activity. A urinary tract infection may present with cloudy or unpleasant-smelling urine, burning, urgency or lower abdominal discomfort. A kidney infection can cause fever, chills, feeling unwell and pain in the back or side. The appearance and smell alone cannot identify the cause.

Drink fluids regularly if you have not been advised to limit them, and observe whether the urine becomes paler. Do not use leftover antibiotics or someone else's medicine. Arrange a GP or pharmacy assessment if the change lasts, returns, or comes with burning, urgency, blood or pain. A urine sample may help distinguish infection from other causes, and the clinician may ask about medicines, discharge, recent illness and fluid intake.

Seek prompt medical care for fever, chills, vomiting, pain in the flank or back, marked weakness, blood in the urine, or difficulty passing urine. These features can occur with a kidney infection or an obstruction and should not be managed by waiting at home. Seek emergency help if you are confused, faint, severely unwell or unable to keep fluids down.

Do I need a urine test or culture? Could dehydration, a medicine or food explain the smell? Which symptoms would suggest the infection has reached the kidneys? How should I manage fluids while waiting for results?