Compartment syndrome occurs when increased pressure within a closed muscle compartment compromises blood flow, potentially causing tissue damage. It can be acute, such as from fractures or crush injuries, or chronic in athletes. Acute compartment syndrome is a medical emergency requiring fasciotomy to release pressure. Chronic exertional compartment syndrome typically affects runners and causes pain with exercise that resolves after stopping. Diagnosis involves symptoms and ruling out other causes; fasciotomy may be needed if conservative measures fail to provide relief from chronic compartment syndrome.