An adolescent patient with post-thrombotic syndrome achieves excellence in sport.

The reported incidence of post-thrombotic syndrome (PTS) following deep venous thrombosis (DVT) in children has increased. Diagnosis of PTS is reliant on assessment of clinical signs and self-report of physical symptoms. We present the case of an 11-year-old young man, diagnosed with a spontaneous lower-limb DVT, who developed significant clinical signs of severe PTS with no apparent physical symptoms. In adolescence, the patient participated in high-level competitive sport with no reported functional limitations. This case highlights that reliance on the severity of only clinical signs without an understanding of a child's physical abilities limits the assessment of PTS.