Environment is classified as internal and external.
Internal Environment: refers to each and every component, every tissue, organ and organ-system and their harmonious functioning within the system.
External Environment (Macro Environment): It consists of the things to which man is exposed after conception. It is defined as everything external to the individual human host. This can be divided into physical, biological and psychosocial components, which can affect health and susceptibility to illness.
Micro Environment: Domestic environment or personal environment which includes individual’s way of living and life style like
Eating habits
Smoking
Drinking
Use of drugs.
Occupational environment, Socio economic environment and moral environment also act as determinants of health.
If the environment is favorable to the individual he can make full use of his physical and mental capabilities.