Analgesics are the substances, that reduce pain which may be due to swelling of tissues, injury, inflammation or some other disorders. Analgesics are of two types:
Narcotic analgesics are the ones which induce sleep and thus help to reduce the feeling of pain. Alkaloids present in opium, viz. morphine, codeine, etc. are common examples of narcotics. In higher doses these may cause unconsciousness. These are habit-forming and cause addiction. Due to addiction a person wants to have it regularly and in larger amounts. Such a person feels upset and uncomfortable if he does not get it.