Bad-smelling, cloudy urine: what to know

Cloudiness may come from crystals, mucus, cells or other material in urine. A strong odour can occur when urine is concentrated, especially after sweating, vomiting or drinking little. Some foods, vitamins and medicines can also alter smell. A urinary tract infection may cause cloudy or unpleasant-smelling urine alongside burning when passing urine, urgency, frequent trips or lower abdominal discomfort. A kidney infection can add fever, chills, pain in the side or back, nausea, or feeling markedly unwell. Cloudy urine alone does not identify the cause.

Drink fluids regularly if you have not been told to restrict them, and observe whether the urine becomes clearer. Do not use leftover antibiotics or take someone else’s medicine. Note when the change began, its colour, any new foods or medicines, and symptoms such as burning, urgency or pain. Arrange a clinical assessment if the change persists, returns, or is accompanied by urinary symptoms; a urine test may help distinguish infection from other causes.

Seek urgent medical help for fever with flank or back pain, vomiting, confusion, severe weakness, or difficulty passing urine. Blood in the urine, pregnancy, a weakened immune system, or known kidney problems also warrant prompt advice. Sudden severe illness should not be explained away as dehydration.

Could a urine test check for infection or blood? Which symptoms would suggest a kidney infection? Should any current medicine, supplement or food be considered? How much fluid is suitable for me?