Spanish versions are available for most of the diseases and conditions pages. See the full list of diseases and conditions in Spanish or go to the English page and click the link on the right side of the page. Viruses are the most common cause of hepatitis, but the condition can also be caused by other infections, heavy alcohol use, toxins, certain medications, and autoimmune disease. There are five main virus types that cause hepatitis—type A, B, C, D, and E. Dengue fever is an infectious disease carried by mosquitoes and caused by any of four related dengue viruses. This disease used to be called “break-bone” fever because it sometimes causes severe joint and muscle pain that feels like bones are breaking.
Medical disorders can be categorized into mental disorders, physical disorders, genetic disorders, emotional and behavioral disorders, and functional disorders. The term disorder is often considered more value-neutral and less stigmatizing than the terms disease or illness, and therefore is preferred terminology in some circumstances. While the term medical condition generally includes mental illnesses, in some contexts the term is used specifically to denote any illness, injury, or disease except for mental illnesses.
In a fundamental sense, therefore, disease represents the consequences of a breakdown of the homeostatic control mechanisms. In some instances, the affected mechanisms are clearly indicated, but in most cases, a complex of mechanisms is disturbed, initially or sequentially, and a precise definition of the pathogenesis of the ensuing disease is elusive. There are several measures used to quantify the burden imposed by diseases on people. The years of potential life lost is a simple estimate of the number of years that a person’s life was shortened due to a disease. For example, if a person dies at the age of 65 from a disease, and would probably have lived until age 80 without that disease, then that disease has caused a loss of 15 years of potential life. YPLL measurements do not account for how disabled a person is before dying, so the measurement treats a person who dies suddenly and a person who died at the same age after decades of illness as equivalent.
Health experts have known about dengue fever for more than 200 years. The autoimmune lymphoproliferative syndrome is a rare genetic disorder of the immune system first described by NIH scientists in the mid-1990s that affects both children and adults. In ALPS, unusually high numbers of white blood cells called lymphocytes accumulate in the lymph nodes, liver, and spleen and can lead to the enlargement of these organs.
Without an agreed-on definition, different researchers may report different numbers of cases and characteristics of the disease. Treatment for medical emergencies must be provided promptly, often through an emergency department or, in less critical situations, through an urgent care facility. Alternatively, diseases may be classified according to the organ system involved, though this is often complicated since many diseases affect more than one organ. The study of disease is called pathology, which includes the study of etiology, or cause. Mayo Clinic is a nonprofit organization and proceeds from Web advertising help support our mission.
MedTerms online medical dictionary provides quick access to hard-to-spell and often misspelled medical definitions through an extensive alphabetical listing. Plague, caused by the bacterium Yersinia pestis, is a disease that affects humans and other mammals. People typically get infected after being bitten by a rodent flea that is carrying the bacterium or by handling a plague-infected animal. Without prompt treatment, the plague can cause serious illness or death. HIV, or human immunodeficiency virus, is the virus that causes AIDS and can be transmitted during sexual intercourse; by sharing syringes; or perinatally during pregnancy, childbirth or breastfeeding. Since the first AIDS cases were reported in 1981, HIV/AIDS has been one of humanity’s deadliest and most persistent epidemics.
Although extraordinary progress has been made in the fight against new HIV cases and AIDS deaths, the HIV pandemic continues. More than 80 diseases occur as a result of the immune system attacking the body’s own organs, tissues, and cells. Some of the more common autoimmune diseases include type 1 diabetes, rheumatoid arthritis, systemic lupus erythematosus, and inflammatory bowel disease. Treatments are available for many autoimmune diseases, but cures have yet to be discovered. Provincial Health Services Authority improves the health of British Columbians by seeking province-wide solutions to specialized health care needs in collaboration with BC health authorities and other partners.