[1] Severe enlargement of the tongue can cause cosmetic and functional difficulties in speaking, eating, swallowing and sleeping.

Signs and symptoms include: A tongue that constantly protrudes from the mouth is vulnerable to drying out, ulceration, infection or even necrosis.

[5] The most common causes of tongue enlargement are vascular malformations (e.g. lymphangioma or hemangioma) and muscular hypertrophy (e.g. Beckwith–Wiedemann syndrome or hemihyperplasia).

[3] Enlargement due to lymphangioma gives the tongue a pebbly appearance with multiple superficial dilated lymphatic channels.

In edentulous persons, a lack of teeth leaves more room for the tongue to expand into laterally, which can create problems with wearing dentures and may cause pseudomacroglossia.

Beckwith–Wiedemann syndrome is a rare hereditary condition, which may include other defects such as omphalocele, visceromegaly, gigantism or neonatal hypoglycemia.

Definitions of macroglossia have been proposed, including "a tongue that protrudes beyond the teeth during [the] resting posture" and "if there is an impression of a tooth on the lingual border when the patients slightly open their mouths".

[14] Pseudomacryglossia refers to a tongue that is of normal size but gives a false impression of being too large in relation to adjacent anatomical structures.