Differential Diagnosis for Dark Colored Urine

• Single most likely diagnosis
  • Dehydration: This is the most common cause of dark-colored urine, as the concentration of the urine increases when the body has low fluid levels, resulting in a darker appearance.
• Other Likely diagnoses
  • Liver disease (e.g., hepatitis, cirrhosis): Liver conditions can cause changes in urine color due to the buildup of bilirubin, a yellow pigment that can turn urine dark.
  • Kidney disease (e.g., kidney stones, kidney failure): Kidney problems can lead to concentrated urine, resulting in a darker color.
  • Urinary tract infection (UTI): Certain UTIs, especially those caused by bacteria, can cause urine to appear darker or cloudier.
  • Medications (e.g., certain antibiotics, laxatives): Some medications can alter urine color, making it appear darker.
• 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 urine, which can cause it to appear dark or tea-colored.
  • Hemolytic anemia: A condition where red blood cells are destroyed, releasing hemoglobin into the urine, which can cause it to appear dark or black.
  • Malignant melanoma: In rare cases, melanoma can cause urine to appear dark due to the presence of melanin.
• Rare diagnoses
  • Alkaptonuria: A rare genetic disorder that affects the breakdown of certain amino acids, resulting in dark-colored urine.
  • Porphyria: A group of rare genetic disorders that can cause urine to appear dark or purple due to the accumulation of porphyrins.
  • Blackwater fever: A rare complication of malaria that can cause urine to appear dark or black due to the presence of hemoglobin.