The hallmark symptom of compartment syndrome is severe pain that does not go away when you take pain medicine or raise the affected area. In more advanced cases, symptoms may include:

• Decreased sensation
• Paleness of skin
• Weakness

A physical exam will reveal:

• Severe pain when moving the affected area (for example, a person with compartment syndrome in the foot or lower leg will experience severe pain when moving the toes up and down)
• Tensely swollen and shiny skin
• Pain when the compartment is squeezed

Confirming the diagnosis involves directly measuring the pressure in the compartment. This is done using a needle attached to a pressure meter into the compartment. The needle is inserted into the affected area. Compartment syndrome is diagnosed if the pressure is greater than 45 mmHg or when the pressure is within 30 mmHg of the diastolic blood pressure (the lower number of the blood pressure).

When chronic compartment syndrome is suspected, this test must be performed immediately after the activity that causes pain.