Background: Medical affirmation, including gender-affirming hormones, is an essential component in the treatment of many transgender and gender-diverse youth. The risk of venous thromboembolism (VTE) during testosterone therapy for gender-affirming care is not fully elucidated.
Observation: The case describes a 17-year-old transgender male treated with testosterone therapy who presented with an occlusive deep vein thrombosis of right axillary and subclavian veins.