What is Disease?
[[File:Poumon artificiel.jpg|thumb|Examining a patient in a tank respirator]] A '''disease''' or '''medical condition''' is an unhealthy state where something bad happens to the [[human body|body]] or [[mind]].<ref>{{DorlandsDict|three/000030493|Disease}}</ref> Diseases can cause [[pain]], parts of the body to stop working the right way, or death. The word ''disease'' is sometimes used to include: * parts of the body being hurt, * not having the usual abilities, * medical problems or [[syndrome]]s, * [[infection]]s by [[microorganism]]s, * feeling unhealthy, such as having pain or feeling hot (called [[symptom|'symptoms']]), * unusual shapes of body parts. == Causes == A disease can be caused by many things. Sometimes [[germ]]s enter our body through food, water or air. A person can be [[Infection|infected]] by infectious agents like [[bacteria]], [[virus]]es or [[fungus]]. Disease can also be caused by eating bad or old [[food]]s. There are small [[Pathogen|germs]] in old foods that can cause diseases. Sometimes the [[germs]] produce [[chemicals]] or [[toxin]]s which causes the disease. One of the most common causes of disease is poor [[sanitation]] and lack of clean water. Some deadly diseases like [[malaria]] in [[tropical]] parts of the world are spread by a [[mosquito]]. Animals that spread disease are called ''vectors''. There are many vectors, including snails, ticks, and fleas. Some people are born with '[[Genetics|genetic]] diseases'. These are diseases because of an error or [[mutation]] in a person's [[DNA]]. An example of a mutation is [[cancer]]. Living or working in an unhealthy [[environment]] can also be a cause for diseases. Diseases are more common in older people. == Treatments == Some diseases can be helped with [[medicine]]. [[Infection]]s can often be cured by [[antibiotics]], though [[resistance to antibiotics]] is a problem. Some disease may be helped by [[surgery]]. Not every disease can be helped with medicine or surgery, though. Some diseases must be treated during the w