Did "Mona Lisa" have thyroid disease?

The authors said that hypothyroidism could be a “unifying diagnosis” that would explain many features in the painting, including the subject’s apparent yellowing skin; thinning hair and lack of eyebrows along with a receding hairline; a possible enlargement in the neck suggestive of a goiter; as well as the previously suggested symptoms of hyperlipidemia.

Mehra and Campbell also noted that Gherardini had given birth a few months before sitting for the portrait, and pregnancy can sometimes be a cause of hypothyroidism.