Diseases can be classified into
Communicable and Non-Communicable
Infectious and Non-infectious
Diseases are classified majorly based on whether it is transmitted from one person to another. A disease is said to be infectious or communicable if it occurs due to an external factor and is transmitted from person to person. Example: Malaria and Rabies.
A disease is said to be non-infectious or non-communicable if it can not be transmitted from one person to another. Example: Cancer and Rickets.