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:
“His poor self,
A dedicated beggar to the air,
With his disease of all-shunned poverty,
Walks, like contempt, alone.”
—William Shakespeare (1564–1616)
“In a country where misery and want were the foundation of the social structure, famine was periodic, death from starvation common, disease pervasive, thievery normal, and graft and corruption taken for granted, the elimination of these conditions in Communist China is so striking that negative aspects of the new rule fade in relative importance.”
—Barbara Tuchman (1912–1989)
“Sadism is not an infectious disease that strikes a person all of a sudden. It has a long prehistory in childhood and always originates in the desperate fantasies of a child who is searching for a way out of a hopeless situation.”
—Alice Miller (20th century)