Disease is a condition that impairs the proper functioning of the body or its parts. A disease can be defined as: Any deviation from normal functioning or state of complete physical and mental well being.
Types of diseases:
The human diseases are broadly classified into following four categories:
- Acute diseases
- Chronic diseases
- Congenital diseases
- Acquired diseases
Diseases such as influenza are described as acute because their effects are come on suddenly and affect the body quickly, e.g., common cold.
Other diseases are more long-term, with the symptoms lasting for months or years. Such diseases are called chronic diseases, e.g., tuberculosis.
These diseases are present since birth. They are caused due to genetic abnormality or due to metabolic disorders or malfunctioning of any organ. They are permanent, generally not easily curable and may be inherited to the children. For example, colour blindness.
These diseases are those which develop after birth. Acquired diseases can be classified into two types:
- Infectious or communicable diseases.
- Non-infectious or non-communicable diseases.