A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune diseases. In humans, "disease" is often used more broadly to refer to any condition that causes pain, dysfunction, distress, social problems, or death to the person afflicted, or similar problems for those in contact with the person. In this broader sense, it sometimes includes injuries, disabilities, disorders, syndromes, infections, isolated symptoms, deviant behaviors, and atypical variations of structure and function, while in other contexts and for other purposes these may be considered distinguishable categories. Diseases usually affect people not only physically, but also emotionally, as contracting and living with many diseases can alter one's perspective on life, and their personality.
Death due to disease is called death by natural causes. There are four main types of disease: pathogenic disease, deficiency disease, hereditary disease, and physiological disease.
Diseases can also be classified as communicable and non-communicable disease.
Read more about Disease: Causes and Transmissibility, Burdens of Disease, Prevention, Treatments, Epidemiology, Social and Cultural Responses
Famous quotes containing the word disease:
“Smoking ... is downright dangerous. Most people who smoke will eventually contract a fatal disease and die. But they don’t brag about it, do they? Most people who ski, play professional football or drive race cars, will not die—at least not in the act—and yet they are the ones with the glamorous images, the expensive equipment and the mythic proportions. Why this should be I cannot say, unless it is simply that the average American does not know a daredevil when he sees one.”
—Fran Lebowitz (b. 1950)
“It is useless to check the vain dunce who has caught the mania of scribbling, whether prose or poetry, canzonets or criticisms,—let such a one go on till the disease exhausts itself. Opposition like water, thrown on burning oil, but increases the evil, because a person of weak judgment will seldom listen to reason, but become obstinate under reproof.”
—Sarah Josepha Buell Hale 1788–1879, U.S. novelist, poet and women’s magazine editor. American Ladies Magazine, pp. 36-40 (December 1828)
“Anti-Semitism is a horrible disease from which nobody is immune, and it has a kind of evil fascination that makes an enlightened person draw near the source of infection, supposedly in a scientific spirit, but really to sniff the vapors and dally with the possibility.”
—Mary McCarthy (1912–1989)