Differential Diagnosis for Dark Brown Urine
- Single most likely diagnosis
- Dehydration: This is often the most common cause of dark brown urine, as it results from a concentrated urine output due to insufficient fluid intake or excessive fluid loss.
- Other Likely diagnoses
- Urinary Tract Infection (UTI): A UTI can cause changes in urine color, including dark brown, due to the presence of blood, bacteria, or other substances.
- Kidney Stones: Kidney stones can cause blood to appear in the urine, leading to a dark brown color.
- Liver Disease: Certain liver conditions, such as hepatitis or cirrhosis, can cause changes in urine color due to the buildup of bilirubin.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Rhabdomyolysis: This is a serious condition where muscle tissue breaks down, releasing myoglobin into the bloodstream, which can cause dark brown urine. If left untreated, it can lead to kidney failure.
- Malignant Melanoma: In rare cases, melanoma can cause dark brown urine due to the presence of melanin. Early detection is crucial for treatment.
- Rare diagnoses
- Alkaptonuria: A rare genetic disorder that affects the breakdown of certain amino acids, leading to dark brown urine due to the accumulation of homogentisic acid.
- Porphyria: A group of rare genetic disorders that can cause changes in urine color, including dark brown, due to the buildup of porphyrins.
- Blackwater Fever: A rare complication of malaria that can cause dark brown or black urine due to the presence of hemoglobin.