Multiple sclerosis is an inflammatory demyelinating disease of the CNS in which activated immune cells invade the central nervous system and cause inflammation, neurodegeneration, and tissue damage.

Asthma is a common pulmonary condition defined by chronic inflammation of respiratory tubes, tightening of respiratory smooth muscle, and episodes of bronchoconstriction.

HIV is commonly transmitted via unprotected sexual activity, blood transfusions, hypodermic needles, and from mother to child.

Pathophysiology is a study which explains the function of the body as it relates to diseases and conditions.