Upper extremity deep vein thrombosis (UEDVT) is extremely rare in children and adolescents. Paget - Schroetter Syndrome (PSS) is the primary, spontaneous thrombosis of the subclavian venous (SV) axillary tract. Herein, we report on PSS in two children who did regular body building exercises. 16-year-old two male patients admitted with complaints of swelling, coldness and pain on the right upper extremity. Their recent history disclosed that they have been doing advanced body building exercises for the last year. Physical examination revealed a difference of 4 cm and 5 cm in the diameter of each arm, as well as coldness and venous engourgement in the upper extremities. An acute thrombus was present in the proximal right SV lumen and no flow was detected on upper extremity venous doppler ultrasaund. Surgical treatment was performed in addition to medical thrombosis treatment. Early diagnosis and treatment of PSS is important for better outcomes. PSS should be considered in young patients with UEDVT, especially those with a history of vigorious exercise.

Keywords: thrombosis, exercises, Paget - Schroetter Syndrome