Concept and Determinants of Health

A state of complete physical, mental and social well-being and not merely the absence of disease or infirmity, is called health.

• Health was earlier thought to depend on a balance of body 'humours' (Hippocrates, Ayurveda), disproved by William Harvey through blood circulation and the use of the thermometer.
• The mind influences the immune system via the nervous and endocrine systems, so mental state affects health.
• Health is affected by genetic disorders, infections, and lifestyle (diet, exercise, rest, habits).
• Health = state of complete physical, mental, and social well-being, not just the absence of disease.
• Good health improves efficiency, longevity, and reduces infant and maternal mortality.
• Maintained by a balanced diet, hygiene, exercise, yoga, vaccination, and proper waste/vector control.
• A disease occurs when organ function is disrupted, as evidenced by signs and symptoms.
• Diseases are infectious (e.g., AIDS) or non-infectious (e.g., cancer); drug and alcohol abuse also harm health.