My urine smells bad and is dark yellow and cloudy: what should I know?

Urine colour and odour can change after sweating, vomiting, diarrhoea, eating certain foods, or taking some vitamins and medicines. Cloudiness may come from crystals, mucus, blood cells or white blood cells. The appearance alone cannot identify the cause.

Dehydration makes urine more concentrated, which can make it darker and stronger-smelling. If the urine becomes clearer and paler after you replace lost fluids, concentration may have contributed.

A urinary tract infection can present with cloudy or strong-smelling urine, often alongside burning when passing urine, needing to go frequently, urgency, or discomfort low in the abdomen. A kidney infection can present with urinary changes as well as fever, chills, pain in the side or back, nausea, or feeling very unwell.

Cloudy urine without pain can still deserve attention when it persists, returns repeatedly, or contains visible blood. Vaginal discharge or semen can also mix with a urine sample and make it look cloudy.

Drink water regularly unless a clinician has told you to restrict fluids. If you have recently lost fluid through heat, exercise, vomiting or diarrhoea, take small, frequent sips. Do not use leftover antibiotics or someone else’s prescription.

Notice whether the change settles as you return to your usual fluid intake. Keep track of burning, urgency, frequency, pain, fever, discharge and any blood. A clinician may test a fresh urine sample, especially if symptoms continue or infection is suspected.

Arrange medical advice promptly if the urine changes persist, you have pain or burning when urinating, or you develop urgency, frequent urination, lower abdominal pain or visible blood.

Seek urgent care for fever or chills with urinary symptoms, pain in your side or back, vomiting, confusion, faintness, or difficulty passing urine. If you are pregnant, have kidney disease, use a urinary catheter, or have a weakened immune system, contact a clinician early when infection symptoms appear.

Ask: Could dehydration, a medicine, supplement or food explain the change? Do my other symptoms suggest a urinary tract infection? Should I provide a urine sample, and which warning signs mean I should return urgently?