Acute carpal tunnel syndrome is the most common compression neuropathy of the upper extremity following trauma. A rare occurence of spontaneous bleeding into the carpal tunnel, presenting as acute carpal tunnel syndrome, is presented.Key Words: Carpal tunnel syndrome; Spontaneous bleeding Syndrome du tunnel carpien aigu consécutif à une hémorragie spontanée Le syndrome du tunnel carpien est la neuropathie par compression la plus fréquente à survenir au niveau des membres supérieurs par suite de traumatismes. On présente ici un cas rare d'hémorragie spontanée au niveau du tunnel carpien ayant donné lieu à un syndrome aigu du tunnel carpien. C lassic carpal tunnel syndrome (CTS) occurs most often in women, and manifests as hypoesthesia and tingling in the median nerve distribution distal to the wrist joint. In acute CTS (ACTS), the intracarpal interstitial pressure rises above the threshold, and capillary blood flow is reduced below the level of median nerve viability. This leads to ischemia of the muscles and nerves, resulting in the clinical signs and symptoms. ACTS due to spontaneous bleeding into the carpal tunnel is rare. We report a patient who developed ACTS from spontaneous bleeding into the carpal tunnel following strenuous exercise. CASE PRESENTATIONA 51-year-old man presented to the emergency department with acute pain and swelling of the right hand following a workout at a gym. He had no history of serious illness in the past. Medications included acetylsalicylic acid (81 mg/day) and vitamin E once per day. His pain started after his workout and increased over a 2 h period. There was no history of trauma. His hematological work-up was negative. He complained of tingling and paresthesia of the median nerve distribution.On examination, there was swelling of the hand with slight bluish discolouration (Figure 1). The wrist was maintained in a flexed position. The signs and symptoms were those of acute tenosynovitis originating in the common flexor synovial sheath at the wrist with associated paresthesia in the distribution area of the median nerve in the hand.X-rays of the wrist and hand were negative. A clinical diagnosis of ACTS was made. He underwent decompression of the carpal tunnel under general anesthesia. At exploration, blood was seen inside the carpal tunnel (Figure 2). The carpal tunnel was decompressed. His symptoms improved following decompression and at six weeks he had full function of the hand.