A feeling of unpleasant sensation or pressure on a particular part of the body as a result of tissue disease or damage is known as pain. Though stressful, it is a protective warming mechanism that helps to prevent further damage. However, chronic pain often does not have any useful function.
Everyone experiences pain due to some or the other reason, and the cause determines the type and severity of it. For instance, the pain caused by a sports injury may be less severe than that of a similar injury caused by a violent assault or an accident. It is important to relax to relieve the pain, as fear and anxiety can only make it worse.
The brain and spinal cord produce endorphins, which work as painkillers. They are natural chemicals that are closely related to morphine, and act as highly effective pain relievers for short period. However, they are less effective during the times of chronic pain.
Specialised nerve endings are known as pain receptors, and they get stimulated when the tissue is damaged by trauma, infection or a problem with its blood supply. Electrical signals travel along the nerves and through the spinal cord to the brain, which interprets them as pain. Meanwhile, a chemical known as prostaglandins is released by the damaged tissues, which causes inflammation and swelling. The prostaglandins further stimulate the receptors. The skin and other sensitive parts of the body, such as tongue and eyes, have a large number of pain receptors and they are therefore very sensitive to painful stimuli. As the internal organs of the body have fewer pain receptors, they are insensitive to most types of injury.