Some persons are much more liable to become faint than others, and there is often a good deal of peculiarity with respect to the acting cause. Certain objects of sight will cause some to become faint immediately, for example accidents or their consequences, which injure the human body, and cause effusion of blood. Certain smells affect others, and cause immediate faintness; even the scent of a rose can cause this effect. Affections of the mind, and sudden emotions, debility, habitual or temporary, weakness of the heart itself and loss of blood. Whatever depresses the power of the organ of circulation is apt to produce faintness.
A person about to faint becomes affected with ringing in the ears, the sight fails, ideas are confused, and the mind incapable of exertion; the countenance becomes deadly pale, cold sweat breaks out over the forehead, the power over the limbs either becomes very unsteady or fails altogether, and if actual fainting happens, the individual sinks down, and is really in a condition which much resembles death, and might pass into death.
The condition of diminished blood circulation through the brain must be altered immediately; and for this the individual should be laid flat, the head level with the body, so the feebly acting heart may not have to propel the blood upward, but horizontally. The neck and chest should be exposed, fresh air admitted freely, a little water sprinkled on the face, and stimulant vapours, such as ammonia, held to the nostrils at intervals. Sal volatile or a little spirits, wine or water; or 20 to 30 minims of chloric ether, if the person can swallow, may be given. Nitrate of amyl is found useful, and being inhaled only, is more easily administered.
From A Dictionary of Domestic Medicine and Household Surgery, by Spencer Thomson MD LRCS and J C Steele MD, published in 1882 by Charles Griffin and Company, London.