What should you know about cloudy and dark urine?

Urine can become dark when the body has lost fluid through heat, sweating, vomiting, or diarrhea. Cloudiness may be caused by crystals, mucus, cells, or infection. Heat exhaustion can include heavy sweating, weakness, dizziness, headache, nausea, and dark urine. Liver inflammation, including hepatitis A or hepatitis B, may be associated with dark urine plus yellowing of the skin or eyes, pale stools, nausea, or unusual tiredness. These patterns are clues, not a diagnosis.

Move to a cool place if heat exposure is involved, rest, and take fluids in small, regular amounts if you can drink safely. Record when the urine changed and any fever, vomiting, abdominal discomfort, yellowing, or reduced urination. Contact a clinician if the color remains dark, the cloudiness recurs, or you have symptoms beyond mild thirst. Mention recent travel, sick contacts, new medicines, supplements, and alcohol use.

Seek urgent medical care for confusion, fainting, severe weakness, repeated vomiting, inability to drink, very little urine, severe abdominal pain, or yellow skin or eyes with worsening illness. Fever with marked weakness after heat exposure also deserves prompt attention.

Ask whether you need urine and blood tests, whether heat or fluid loss explains the change, and which warning signs matter for you. Share the timing, amount of fluid loss, and any liver-related symptoms.