The night-make; (from incubo, to lie on; ephialtes, from to leap upon; epibole, from to press on; because the patient imagines that something leaps or presses upon him; and babuzicarius, from to speak inarticulately, because, in his distress, he mutters indistinctly). There is also a species called succubus. The Incubus is synonymous with oneirodynia in Dr. Cullen's system.

This complaint always happens during sleep: the patient suddenly feels a sense of weight, a dread of suffocation, an oppression as from somebody falling upon him, with an intent to deprive him of life, not suffering him to cry out; hence it is usual with these patients to start up and exclaim with a confused inarticulate voice: they move with difficulty, but, on the first motion, the distressing feelings vanish.

This disorder hath been supposed to proceed from a stagnation of blood in the brain and lungs; but it is a nervous affection, chiefly from indigestion: and those whose nerves are weak, who lead sedentary lives, feed heartily, and sup late, are the most subject to it. Wind is a frequent cause: deep thought, anxiety, or any oppression of mind, equally produces it. It is said that none are attacked with the ephialtes but when laid on their backs. A sense of suffocation, rousing the patient from sleep, has been styled an ephialtic symptom, distinguishing hydrothorax; but, in this case, there is no sense of a heavy weight on the praecordia.

If the patient hath a sanguine plethora, bleeding, a spare diet, aloetic purges, relieve the complaint. Dr. Whytt says that he generally found a glass of brandy, if taken at bed time, would prevent the attack. A slight supper, cheerfulness before bed time, due exercise during the day, are the best remedies; but if these fail, the fetid gums, with camphor joined to opium, at bed time, will succeed.

See Coelius Aurelianus de Morbis Chronicis, lib. i. cap. 3. Lommii Observationes Medicinales, iii. P. AEgineta, lib. iii. c. 15. Soranus's Aitiologoumena.