Myofascial pain is a chronic condition that affects the fascia, or connective tissue that covers the muscles. Myofascial pain typically presents as a deep aching pain due to inflammation in the body's soft tissues. It can involve either a single muscle, or a muscle group. It is presumed that an injury or overuse to a muscle/muscle group may lead to the development of a trigger point, which in turn can cause pain in other areas. This is known as referred pain. Myofascial pain can be made worse with activity or stress.