DEFINITION – A disease is a particular abnormal condition, a disorder of a structure or function, that affects part or all of an organism. The study of disease is called pathology which includes the causal study of etiology. Disease is often construed as a medical condition associated with specific symptoms and signs. It may be caused by external factors such as pathogens, or it may be caused by internal dysfunctions particularly of the immune system such as an immunodeficiency, or a hypersensitivity including allergies and autoimmunity.
INFORMATION – 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 can affect people not only physically, but also emotionally, as contracting and living with a disease can alter the affected person’s perspective on life.
DEATH RISK INVOLVED – Death due to disease is called death by natural causes. There are four main types of disease: infectious diseases, deficiency diseases, genetic diseases, and physiological diseases. Diseases can also be classified as communicable and non-communicable. The deadliest diseases in humans are coronary artery disease, followed by cerebrovascular disease and lower respiratory infections.
Acquired disease : disease that began at some point during one’s lifetime, as opposed to disease that was already present at birth, which is congenital disease. “Acquired” sounds like it could mean “caught via contagion”, but it simply means acquired sometime after birth. It also sounds like it could imply secondary disease, but acquired disease can be primary disease.
Acute disease : disease of a short-term nature ; the term sometimes also connotes a fulminant nature
Chronic disease : disease that is a long-term issue
Congenital disease : disease that is present at birth. It is often, genetic and can be inherited. It can also be the result of a vertically transmitted infection from the mother such as HIV/AIDS.
Genetic disease : disease that is caused by genetic mutation. It is often inherited, but some mutations are random and de novo.
Hereditary or inherited disease : a type of genetic disease caused by mutation that is hereditary
Iatrogenic disease: A disease condition caused by medical intervention. Idiopathic disease : disease whose cause is unknown. As medical science has advanced, many diseases whose causes were formerly complete mysteries have been somewhat explained or even extensively explained .
Incurable disease : disease that cannot be cured
Primary disease : disease that came about as a root cause of illness, as opposed to secondary disease, which is a sequela of another disease
Secondary disease : disease that is a sequela or complication of some other disease or underlying cause . Bacterial infections can be either primary or secondary to a viral infection or burn, which predisposed by creating an open wound or weakened immunity .
Terminal disease : disease with death as an inevitable result Illness.