A trigger point is a discrete, focal, hyperirritable spot located in a taut band of skeletal muscle. These spots are painful on compression and can produce referred pain, referred tenderness, motor dysfunction, and autonomic phenomena. Trigger points are classified as being active or latent, depending on their clinical characteristics. An active trigger point causes pain at rest and is tender to palpation with a referred pain pattern that is similar to the patients pain complaint. This referred pain is felt not at the site of the trigger-point origin, but remote from it. The pain is often described as spreading or radiating. Referred pain is an important characteristic of a trigger point and differentiates it from a tender point, which is associated with pain at the site of palpation only. Trigger points can cause myofascial pain syndrome, which is a common painful muscle disorder. Treatment options include physical therapy, trigger point injections, pain medications, and relaxation techniques.