Why do diseases exist?
A disease may be caused by external factors such as pathogens or by internal dysfunctions. For example, internal dysfunctions of the immune system can produce a variety of different diseases, including various forms of immunodeficiency, hypersensitivity, allergies and autoimmune disorders.
How does a disease start?
Infection occurs when viruses, bacteria, or other microbes enter your body and begin to multiply. Disease, which typically happens in a small proportion of infected people, occurs when the cells in your body are damaged as a result of infection, and signs and symptoms of an illness appear.
What is the main cause of infectious diseases?
Infectious diseases are caused by pathogenic microorganisms, such as bacteria, viruses, parasites or fungi; the diseases can be spread, directly or indirectly, from one person to another. Zoonotic diseases are infectious diseases of animals that can cause disease when transmitted to humans.
Why do germs attack our bodies?
Germs can cause disease by upsetting the way the body works. They do this when they: produce toxins (poisons) increase their number greatly by breeding and they can stop parts of the body from working properly, or.
Can diseases cured?
Some diseases can be cured. Others, like hepatitis B, have no cure. Medical professionals use medicine, therapy, surgery, and other treatments to help lessen the symptoms and effects of a disease. Sometimes these treatments are cures — in other words, they get rid of the disease.
Where did Ebola come from?
Ebola virus was first discovered in 1976 near the Ebola River in what is now the Democratic Republic of Congo. Since then, the virus has been infecting people from time to time, leading to outbreaks in several African countries.