Stress injuries represent a spectrum of injuries ranging from periostitis, caused by inflammation of the periosteum, to a complete stress fracture that includes a full cortical break. They are relatively common overuse injuries in athletes that are caused by repetitive submaximal loading on a bone over time. Stress injuries are often seen in running and jumping athletes and are associated with increased volume or intensity of training workload. Most commonly, they are found in the lower extremities and are specific to the sport in which the athlete participates. Upper extremity stress injuries are much less common than lower extremity stress injuries, but when they do occur, they are most commonly seen in the ulna. Similar to the lower extremity injuries, upper extremity stress injuries are the result of overuse and fatigue. Rib stress fractures are an uncommon site of stress injuries. First rib fractures are the most common, and these are seen in pitchers, basketball players, weightlifters, and ballet dancers. Stress fractures in ribs 4 through 9 are seen in competitive rowers, and posteromedial rib stress fractures can be seen in golfers. Stress fractures of the pelvis can be vague clinically and mimic other causes of groin and hip pain, for example, adductor strain, osteitis pubis, or sacroiliitis. The most common location is the ischiopubic ramus and sacrum. These injuries are seen most commonly in runners. Femoral neck stress fractures make up approximately 11% of stress injuries in athletes. The patient complains of hip or groin pain which is worse with weight bearing and range of motion especially internal rotation. There are 2 types of femoral neck stress fractures: tension-type (or distraction) fractures and compression-type fractures. Tension-type femoral neck stress fractures involve the superior-lateral aspect of the neck and are at highest risk for complete fracture; thus, these should be detected early. Compression-type fractures are seen in younger athletes and involve the inferior-medial femoral neck. A trial of non-surgical management can be attempted for patients without a visible fracture line on radiographs in compression type injuries. This injury is common in runners. Stress fractures of the femoral shaft are well documented in the literature, and in one study among military recruits, they represented 22.5% of all stress fractures. Patients typically complain of poorly localized, insidious leg pain often mistaken for muscle injury. An exam is often nonfocal, although the “fulcrum test” test can be used by providers to localize the affected pain and suggest the diagnosis. If there is no evidence of a cortical break on imaging, a non-surgical approach can be attempted. The patella is a rare location for a stress fracture and can be oriented either transverse or vertical. Transverse fractures are at higher risk for displacement and immobilization is recommended. Tibial stress injuries are the most common location of stress reactions and fractures. Medial tibial stress syndrome (MTSS), also known as shin splints or tibial periostitis, can be difficult to distinguish from medial tibial stress fractures. Typically, the patient will be tender over the medial posterior edge of the tibia often made worse with a motor exam. Stress injuries will present with pain during activities of daily living, while MTSS is generally limited to exertional activity. Anterior cortex tibial stress fractures are less common than the posteromedial ones and are found in jumping and leaping athletes. These patients may have the “dreaded black line” on x-ray. They are at a greater risk of nonunion and full cortical break and require aggressive conservative therapy. If that fails, surgical management such as an intramedullary rod or flexible plate is indicated. Stress fractures of the medial tibial plateau are uncommon but can be confused for meniscus injury or pes anserine bursitis, and thus, a high index of suspicion is needed. Fibular stress fractures are common and most commonly located in the lower third of the fibula, proximal to the tibiofibular ligament. Patients will have reproducible pain on palpation of the affected bone. Medial malleolus stress fractures are uncommon. Running and jumping athletes can develop vertical stress fractures at the junction of the medial malleolus and tibial plafond. If full cortical disruption is identified, surgical fixation is typically indicated. Calcaneal stress fractures present as localized tenderness over the heel of the calcaneus posterior to the talus. Patients will have a positive squeeze test. Stress fractures can develop in the navicular, medial cuneiform, and lateral process of the talus. Navicular stress fractures are difficult to diagnose early on and are at high risk of nonunion due to poor vascular flow, primarily in the middle third. These are common in basketball players and runners. They are usually tender on the navicular bone. Metatarsal stress fractures account for 9% of all stress fractures in athletes. The second and third metatarsals are most commonly affected and are usually in the neck or distal shaft. They will be point tender with localized swelling over the affected bone. Dancers fracture is a stress fracture at the base of the second metatarsal. Stress fractures distal to the tuberosity of the fifth metatarsal are termed Jones fractures but must be distinguished from an acute Jones fracture. Sesamoid stress injuries of the great toe present as gradual unilateral plantar pain with the medial (tibial) sesamoid most frequently affected. Direct tenderness or pain with passive extension of the toe aid in diagnosis.