The urinary porphyrins test identifies porphyrins, essential substrates in heme biosynthesis enzymes. Abnormal presence of specific porphyrin isomers suggests porphyria, also seen in liver cirrhosis, infectious mononucleosis, lead poisoning, and viral hepatitis. Healthcare providers rely on this test to diagnose genetic disorders linked to porphyrin synthesis and heavy metal toxicity, aiding in effective management strategies.