SHS is a condition characterized by a palpable or audible “snapping” that occurs around the hip with movement. This condition is further described as either internal snapping hip syndrome (ISHS) or external snapping hip syndrome (ESHS). With ISHS, the “snapping” is felt in the anterior hip region and often involves a tight iliopsoas muscle. With ESHS, the sensation is felt over the lateral hip region and often involves a tight iliotibial band (ITB).

Source : Strength and Conditioning Journal: October 2015 - Volume 37 - Issue 5 - pp 97-104

Snapping Hip Syndrome often affects those involved in sports and dancing, particularly in the 15 - 40 year-old agegroup. The audible snapping can also be accompanied by pain. Episodes can sometimes last months, and require athletes and dancers to stop working and rest.

Other than its obvious links with 'overuse' and straining of the hip joint, its exact cause is unknown.

Also see : Transient synovitis (of the hip)plugin-autotooltip__plain plugin-autotooltip_bigTransient synovitis (of the hip)

Transient synovitis of the hip (a.k.a. Toxic synovitis,Transitory coxitis, Coxitis fugax, Acute transient epiphysitis, Coxitis serosa seu simplex, Phantom hip disease, Observation hip and Irritable hip) is a condition which causes hip pain due to inflammation of the inner lining of the hip joint.