Acute compartment syndrome (ACS) occurs when the pressure within the closed osteo-fascial compartment raises above perfusion pressure leading to irreversible tissue ischemia and necrosis. Any closed compartment in the body can be affected by ACS. The leg is the commonest site. Trauma is the common cause of compartment syndrome in young patients. In older patients, medical causes can cause it. The diagnosis in a conscious patient can be made based on clinical features. Pain out of proportion to the injury is the most important symptom. Exacerbation of pain on stretching the affected muscles and paresthesia are the common signs. Compartment pressure measurement is important for the diagnosis in unconscious and uncooperative patients. The treatment of established ACS is emergency fasciotomy. Untreated compartment syndrome can lead to neurovascular injuries and muscle contractures. In this chapter, we will see the etiologies, clinical features, investigations, and management of acute compartment syndrome of the extremities and the paraspinal region
