Disease

A disease is any kind of disorder in the structure or function of an organism, including humans, plants, and animals. A disease often produces specific symptoms and affects a specific location in the organism’s body. However, a disease is not simply a direct result of physical injury or trauma to the body of the organism. Most of the time, a disease is interpreted as a medical condition with a set of specific symptoms and signs. Disease can be caused by external factors, such as viruses, bacteria, fungi, parasites, proteins, prions, and infections. However, there are also diseases that are caused by dysfunctions within the organism’s body, such as autoimmune diseases. There are for main kinds of disease: deficiency disease, hereditary disease, pathogenic disease, and physiological disease. In many cases, a disease can also be classified as communicable or non-communicable. When used in the context of human patients, a disease is used as a broad term to refer to any physical, mental, or emotional condition that causes dysfunction, pain, distress, problems, or death to the person that is afflicted. The umbrella term of disease can include disorders, syndromes, disabilities, infections, deviant behaviors, unusual variations of structure and function in the body, and even injuries and disabilities. In strict medical context, a disease is an infectious one. Infectious diseases result from the presence of various pathogenic agents, which include (but are not limited to) fungi, bacteria, viruses, multicellular organisms, protozoa, and aberrant proteins called prions. There are diseases that do not immediately manifest; an infection that is does not exhibit symptoms during its incubation period but will produce signs and symptoms at a later time is considered a disease. People who succumb to and die due to the contraction of a disease can be considered to have died of natural causes. This section contains information on disease, which is any kind of disorder in the structure or function of a living organism.