Differential Diagnosis for Brown Urine

• Single most likely diagnosis
  • Dehydration: This is often the most common reason for brown urine, as it concentrates the urine, making it appear darker or brownish.
• Other Likely diagnoses
  • Urinary Tract Infection (UTI): Certain infections can cause changes in urine color, including brown, due to the presence of blood or other substances.
  • Kidney Stones: Stones can cause bleeding in the urinary tract, leading to brown or tea-colored urine.
  • Liver Disease: Conditions like hepatitis or cirrhosis can lead to changes in urine color due to the liver's inability to properly process bilirubin.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Rhabdomyolysis: A serious condition where muscle tissue breaks down, releasing myoglobin into the blood, which can cause brown urine. It requires immediate medical attention.
  • Hemolytic Anemia: Certain types of anemia can cause the breakdown of red blood cells, leading to the release of bilirubin and potentially causing brown urine.
• Rare diagnoses
  • Porphyria: A group of disorders that can lead to the accumulation of porphyrins, which can cause urine to turn brown or other colors.
  • Alkaptonuria: A rare genetic disorder that affects the breakdown of certain amino acids, leading to darkened urine.
  • Melanoma: In rare cases, metastatic melanoma can cause changes in urine color, including brown, due to the release of melanin.