Pain defines a complex interaction between specialized nerves, the spinal cord and the brain. It is an important reaction of the nervous system which warns of possible injury.

Pain is caused when particular nerve endings are stimulated, which might result from damage to the body’s tissue. It can be distinguished between acute and chronic pain: Acute pain describes a sudden pain that usually resolves after a certain amount of time which evolves through an illness, injury or surgery; whereas for chronic pain, the body continuously sends pain signals to the brain, even after the injury healed. As per definition, chronic pain is often defined as pain that lasts more than 12 weeks. Moreover, it may limit a person’s mobility reducing the affected person’s flexibility, strength and endurance and it also may be appearing and disappearing without any specific reason.  Chronic pain, can usually not be cured, but it can be managed to reduce pain and improve function. Some treatment options may be more effective than others. Medications may include over-the counter pain relievers or nonsteroidal anti-inflammatory drugs (NSAIDs), opioid pain relievers or adjuvant analgesics.

Source: Mayoclinic.org; National Institutes of Health (NIH) Medline Plus, Spring (2011); healthline.com