These may be stated together, thus : as causes which are
Hereditary : examples (though not always inherited), consumption, gout, epilepsy, cancer.
Functional: that is, depending upon the action, either too great or too little, of one or more of the organs, or of the body generally. Examples: over-exertion, over-excitement, loss of sleep ; or, on the other hand, want of exercise.
Digestive: as poisoning, unwholesome food, intemperance, abuse of medicine; and, on the other hand, starvation.
Contagious: as small-pox, itch, hydrophobia.