A 43-year-old woman presented to our emergency department with severe bilateral forearm pain. On examination, both forearms were tense and swollen and the patient had excruciating pain, made much worse on passive extension of the fingers. The pain did not resolve with analgesia. The symptoms and clinical examination were highly suspicious for compartment syndrome. However, there was no history of trauma, strenuous physical activity, or any other obvious factor that might have precipitated the onset of a compartment syndrome.