A disease is something that is wrong with the body. It is another word for illness. It is the other main thing that can happen to people as well as injury (trauma).
There are two different types of disease: infectious disease, something that you catch from the environment or other people, and something that goes wrong with the working of your body, such as a cancer.
Infectious diseases are those we get from microbes in the environment, such as bacteria (plague) and viruses like ebola.
When you have a disease, the body recognises this and begins to try to correct the problem. It diverts as much resource as possible to this effort, shutting down other things we might normally do. So we might feel sleepy, not want to do much, we might feel depressed and other conditions. We might also have a high temperature. That is a sign of our body working overtime to sort out a problem usually caused by an infectious disease.
In the case of ebola, only about one in three people are able to fight the virus. For the others it is fatal.
Some viruses are passed on by body fluids or by bites from animals and can be fatal until cures are found. AIDS is a famous one of recent times. Ebola is the one causing great concern at the moment. It can be passed on by touch, or body fluids such as from a sneeze getting on to another person's skin. That is why health workers have to put on protective suits.
Symptoms start up to three weeks after contracting the virus, with a fever, sore throat, muscle pain and headaches. Then, vomiting, diarrhoea and rash usually follows, as well as bleeding internally and externally. If people cannot overcome this virus, they often die from low blood pressure.
