Mona Lisa's Medical Mysteries: From Bell's Palsy to Hypothyroidism

Doctors have long speculated about the health of Lisa Gherardini, the subject of Leonardo da Vinci's Mona Lisa (1503–1506, Louvre, Paris). Her enigmatic smile has been interpreted as a symptom of Bell's palsy, a facial paralysis that can cause unnatural muscle contractions. The condition, sometimes called Mona Lisa syndrome when occurring in pregnant women, aligns with the theory that Gherardini had recently given birth. Other explanations for her closed-mouth smile include tooth loss or bruxism. Yellowish skin, a xanthelasma on the eyelid, thin hair, missing eyebrows and lashes, a swollen neck, and a puffy hand have led to diagnoses of hyperlipidemia (excess fat molecules) or hypothyroidism (underactive thyroid). The latter could also explain a goiter and secondary hyperlipidemia. Some experts propose postpartum thyroiditis as the root cause. Rarer hypotheses include scleroderma, Tourette syndrome, Ehlers-Danlos syndrome, primary biliary cholangitis, Fuchs' heterochromic iridocyclitis, and Parkinson's disease. Despite decades of medical analysis, no definitive diagnosis exists, and the painting's allure persists.