Illness is a harmful physical or psychological disorder of an organism. More specifically, it is a disruption of homeostasis, the self-regulating process in which biological systems maintain their stability by adapting to circumstances. This is often accompanied by symptoms that indicate the abnormal condition. Here is the list of incurable diseases rank by users vote. In the list include physical and mental illnesses.
The visceral leishmaniasis, also known as kala-azar, is an infectious disease caused by a protozoan parasite of the genus Leishmania, affects man and different animal species, primarily the dog. It is the most serious form of leishmaniasis and a major cause of mortality worldwide, occurring between 200000 to 400000 cases in humans per year. There are two species of Leishmania that can cause visceral leishmaniasis. In East Africa and India cases are caused by Leishmania donovani, while in Europe, North Africa and Latin America the agent is Leishmania infantum, also known as Leishmania chagasi. It is endemic in East Africa and India. 90% of cases worldwide occur in only 6 countries: Brazil, Ethiopia, Sudan, South Sudan, India and Bangladesh. The transmission is produced by the bite of mosquitoes of the previously infected genus Phlebotomus or Lutzomyia.
Variola or smallpox was a human infectious disease caused by the Variola major or Variola minor virus. This disease is known as its Latin name Variola or Variola vera, which comes from the Latin word varius, which means "speckled", or varus which means "zit". Smallpox appears in small blood vessels in the skin and in the mouth and esophagus. On the skin, this disease causes a rash, and then a fluid filled wound. Variola major causes a more serious disease with a mortality rate of 30-35%. Minor Variola causes a milder disease also known as alastrim, cottonpox, milkpox, whitepox, and Cuban itch which causes death in 1% of sufferers. The long-term consequences of major Variola infection are scars, generally on the face, which occur in 65–85% of patients.