A disease is a disorder in the function or structure of a part of the body that causes specific signs and symptoms. Additionally, these signs and symptoms do not directly result from physical injury.
There are four main types of diseases:
- Deficiency diseases (e.g., scurvy, hypocalcemia, iron deficiency)
- Infectious diseases (e.g., flu, strep throat, measles, salmonella)
- Physiological diseases (e.g., diabetes, asthma, glaucoma)
- Hereditary diseases (e.g., cystic fibrosis, hemophilia, sickle cell disease, muscular dystrophy)
Disease can affect various body regions or organs. Diseases can also vary based on how harmful they are to the individual or in what way they impact the person with the disease.