Pain can be classified according to it’s duration.

Acute pain: It is the type of pain that occurs soon after an injury. It has a protective role in the sense that it makes a person aware that something is not going right, thus motivating the person to protect himself and prevent further damage. The duration of acute pain is shorter and associated with nausea, vomiting, anxiety, rapid heartbeat, increased breathing rate, elevated blood pressure, sweating and dilated pupils.

Chronic pain: Generally defined as pain lasting 3 months or longer, it may limit the normal functioning of the body or affected part. It may often not have an easily identifiable cause. Usually, it does not affect the heartbeat, breathing rate, blood pressure, or pupils, but may result in other problems such as depression, disturbed sleep, decreased energy, loss of appetite, weight loss, and loss of interest in sexual activity.