• Ptosis (eyelid) (the most common usage of the term), a drooping of the upper or lower eyelid
• Ptosis (breasts), refers to drooping or sagging of the breast. Breast ptosis is related to the laxity of the superficial fascia, suspensory ligaments and skin
• Enteroptosis (intestine), a prolapse or a sinking of the abdominal viscera (internal organs) below their natural position
• Gastroptosis (stomach), the abnormal downward displacement of the stomach. It is not a life threatening condition. The condition frequently causes digestive symptoms and constipation, and is much more prominent in women than men
• Nephroptosis or renal ptosis (kidney)
• Visceroptosis (internal organs), a prolapse or a sinking of the abdominal viscera (internal organs) below their natural position

Ptosis (van het Grieks: Vallen) kan zowel congenitaal als verworven zijn, en in beide gevallen erfelijk.

Het treedt op bij dysfunctie van de Musculus levator palpebrae superioris. Dit kan bijvoorbeeld gebeuren bij het syndroom van Horner en beschadiging van de derde hersenzenuw, de nervus oculomotorius.