Because knowledge of overuse syndromes is limited, the diagnosis and treatment of these conditions are a challenge to sports medicine physicians. Trial and error methods of treatment and too little attention to basic research have resulted in less than optimum solutions. We do know that these maladies most frequently result from overload or repetitive microtrauma stemming from extrinsic factors such as training errors, poor performance, poor techniques and inappropriate surfaces or intrinsic factors including malalignment and muscle imbalance. Overuse injuries involving the muscles include compartment syndromes and muscle soreness; while those involving the tendons result from a variety of degenerative and inflammatory processes. Overstress of bone results in stress fractures, apophysitis and periostitis. Bursitis and joint overstress problems are also discussed briefly. General guidelines for establishing the appropriate diagnosis are: the initial stages of therapy require rest, often a modification or scaled down exposure to the athlete's usual performance rather than complete abstinence; in acutely symptomatic cases pain medications and various measures to control inflammation may be necessary; an exercise programme should start early with range of motion exercises and isometric muscle contractions; when pain allows, dynamic muscle and flexibility exercises can resume together with a conditioning programme; if possible, eccentric exercises should be performed. The treatment may also include other conservative treatment modalities and surgery in special cases. Overuse injuries constitute a great diagnostic and therapeutic problem because the symptoms are often diffuse and uncharacteristic. An appropriate diagnosis followed by adequate treatment can improve or eliminate most of these conditions, but perhaps even more importantly a proper understanding of overuse syndromes should allow physicians to assist athletes, trainers, and coaches in preventing them.