4. Myofascial pain syndrome.
This is a chronic condition that is marked by pressure being placed on trigger points; sensitive spots that are located with the muscles. This pressure can lead to pain in the affected muscle, as well as referred pain, or pain that is felt in another part of the body, though the root cause of the pain is located somewhere else.
Myofascial pain syndrome usually happens when a muscle has been contracted on a repetitive basis; for example, if you repetitively move your arm for work for a pastime, you may develop this condition.
Though most people develop pain related to muscle tension at some point, myofascial pain syndrome is different because it does not go away, but rather it remains and becomes worse over time.
There is no cure, but there are treatments; physical therapy and acupuncture have been found to offer effective pain relief.