What should you know about bad smelling cloudy urine?

Bad-smelling cloudy urine may result from concentrated urine, food or medicines, but it can also occur with a urinary tract infection and needs prompt assessment when pain, fever or other warning signs are present. A temporary change that settles after drinking fluids may be less concerning, while a persistent change or new urinary symptoms deserves medical advice.

Urine can look cloudy when it contains extra salts, mucus, cells or crystals. Dehydration makes urine more concentrated, which can deepen its colour and make its smell stronger. Some foods, supplements and medicines can also alter odour without causing illness.

A urinary tract infection can present with cloudy, strong-smelling urine, often alongside burning when passing urine, an urgent or frequent need to urinate, lower abdominal discomfort or blood in the urine. A kidney infection can cause fever, chills, pain in the side or back, nausea or vomiting. The urine change alone cannot identify the cause.

Drink fluids regularly unless a clinician has told you to restrict them, and notice whether the urine becomes clearer and less strong-smelling. Do not use leftover antibiotics or someone else’s prescription. If the change continues, returns repeatedly, or occurs with burning, urgency, pain or blood, arrange a clinical review. A clinician may ask about medicines and diet and may test a urine sample.

Seek urgent medical care for cloudy, foul-smelling urine with fever, shaking chills, side or back pain, vomiting, marked weakness or confusion. These symptoms can occur when infection has reached the kidneys or is affecting the whole body. Seek prompt advice for visible blood, inability to pass urine, severe pain, or symptoms during pregnancy.

If you feel well but the change does not settle after improving fluid intake, contact a healthcare professional. Earlier assessment is sensible for children, older adults, people with kidney disease, or anyone with a weakened immune system.

You could ask: Could a urine test check for infection or blood? Could any medicine, supplement or recent food explain the smell? What symptoms should prompt urgent review? If treatment is prescribed, how should it be taken and when should improvement be expected?