ABSTRACT
"Red" urine has been recognized for centuries, and its association with disease states has been described. Such red urine may be due to the presence of large quantities of porphyrin in the urine. The red color may also be due to either hemoglobin or myoglobin in the urine. The pigment of red beets and certain other vegetable substances may be excreted in the urine and cause the urine to have a bright red color. Porphyria cutanea tarda symptomatica is a disorder characterized by cutaneous lesions, hyperpigmentation of the skin, evidences of liver disease, and hypertrichosis. Urinary tests for porphyrins and related compounds are useful, but for optimum utility they need to be used in conjunction with other laboratory procedures and clinical observations. For good results in studying urinary porphyrins and related compounds, it is important to recognize the significance and limitations of the information provided.
