Compartment syndrome is a condition in which increased pressure within one of the body's anatomical compartments results in insufficient blood supply to tissue within that space. There are two main types: acute and chronic. Compartments of the leg or arm are most commonly involved.

Symptoms of acute compartment syndrome (ACS) can include severe pain, poor pulses, decreased ability to move, numbness, or a pale color of the affected limb. It is most commonly due to physical trauma such as a bone fracture (up to 75% of cases) or crush injury, but it can also be caused by acute exertion during sport. It can also occur after blood flow returns following a period of poor blood flow. Diagnosis is generally based upon a person's symptoms and may be supported by measurement of intracompartmental pressure before, during, and after activity. Normal compartment pressure should be within 12-18 mmHg; anything greater than that is considered abnormal and would need treatment. Treatment is by surgery to open the compartment, completed in a timely manner. If not treated within six hours, permanent muscle or nerve damage can result.

In chronic compartment syndrome (aka chronic exertional compartment syndrome), there is generally pain with exercise but the pain dissipates once activity ceases. Other symptoms may include numbness. Symptoms typically resolve with rest. Common activities that trigger chronic compartment syndrome include running and biking. Generally, this condition does not result in permanent damage. Other conditions that may present similarly include stress fractures and tendinitis. Treatment may include physical therapy or—if that is not effective—surgery.

Acute compartment syndrome occurs in about 3% of those who have a midshaft fracture of the forearm. Rates in other areas of the body and for chronic cases are unknown. The condition occurs more often in males and people under the age of 35, in line with the occurrence of trauma. Compartment syndrome was first described in 1881 by German surgeon Richard von Volkmann. Untreated, acute compartment syndrome can result in Volkmann's contracture.