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, and/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 a typical 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:
Diseases can also be classified as communicable and
or go back to