Acute compartment syndrome (ACS) is a surgical emergency resulting from increased pressure within a muscle compartment, leading to tissue ischemia. The lower leg is most often affected. Trauma, especially tibial fractures, is the most common cause. Careful clinical exam is critical for prompt diagnosis, though pain may be absent. Compartment pressure monitoring can aid diagnosis but routine use is controversial. Recent focus is on assessing ischemia through blood flow/metabolic changes to improve diagnostic accuracy over pressure thresholds alone. Early identification and treatment of ACS is crucial, as irreversible damage can occur within hours. Careful clinical assessment supplemented by selective use of pressure monitoring facilitates prompt diagnosis.