What causes baldness in people?

There are many theories regarding baldness. Some people treat baldness as the indication of arrival of old age while some are of the view that bald men are intelligent. Baldness is also treated as a sign of richness. Some people think that bald men are fools. Whatever may be the significance of baldness,
one thing is certain that by losing hair, man is deprived of that beauty which otherwise he would have.
Baldness or alopecia is mainly of two types: permanent and temporary. Heredity, age and male sex hormone (androgens) production are three main factors causing permanent baldness. Other causes of permanent baldness are scar producing skin diseases, injuries, inborn lack of hair development and severe injury to hair growing centres by chemical or physical agents.
Temporary baldness may be due to high fever, typhoid, pneumonia, influenza etc. Hair starts falling due to weakness also. Baldness caused by disease and weakness can be cured by nutritive diets and tonics. X-rays, ingestion of metals and drugs, malnutrition, skin disease and endocrine disorders are some other causes of temporary baldness.
Baldness can be controlled to some extent by proper care of hair and balanced diet. No successful drugs or therapies have yet been developed to treat baldness.