Cannabinoid Hyperemesis Syndrome: A Rare Cause of Severe Abdominal Pain and Hyperlactataemia.

Cannabinoid hyperemesis syndrome (CHS) is an emerging disorder in chronic cannabis users, characterized by recurrent nausea, vomiting, severe abdominal pain, and compulsive hot bathing. We report a case of CHS complicated by profound lactic acidosis (lactate 6.1 mmol/L), highlighting this metabolic derangement as a secondary effect of severe dehydration and physiological stress from intractable vomiting and pain. Our case underscores the importance of early recognition of CHS even when abdominal pain predominates, aggressive fluid resuscitation, and targeted therapies including haloperidol and capsaicin. We also review current evidence on CHS pathophysiology, diagnostic criteria, and management strategies, alongside the increasing prevalence in correlation with rising cannabis use in the UK.