Ascher syndrome is classically described as a triad of double upper lip, blepharochalasis, and nontoxic enlarged thyroid of unknown etiology. This condition is rare, presents most often before the age of 20, and is often misdiagnosed. The inheritance pattern is uncertain, although autosomal dominant transmission has been speculated.

Double lip is secondary to labial mucosal hyperplasia and persistence of the horizontal sulcus of the outer cutaneous lip and inner mucosal lip. In most cases, this finding is limited to the upper lip, but rarely the lower lip may be affected.

Blepharochalasis describes lid laxity and sagging formed from repeated episodes of painless edema of the eyelids; it may impede eyesight in severe cases.

Nontoxic thyroid enlargement is found in 10%-50% of cases and is nonessential to the diagnosis. When present, it is not accompanied by abnormal thyroid levels.