Ecstasy (MDMA; 3,4-methylenedioxymethylamphetamine) is an illicit drug that has been increasingly abused by young people. Its effects include euphoria, enhanced sociability and heightened mental awareness. These come about via the increase of serotonin in both the central nervous system and the sympathetic nervous system. Despite the drug's prevalent abuse, serious or adverse effects are rare. Due to personal pharmacokinetics, effects from the same dosage vary according to the individual. Fatal instances may include acute hyponatremia, hyperthermia (>42 degrees C), disseminated intravascular coagulation (DIC) resulting from hyperthermia affecting the kidneys, and non-traumatic rhabdomyolysis. However, it is seldom the case that hyponatremia and hyperthermia co-exist. Hyponatremia is thought to be caused by HMMA - a metabolite of MDMA. Hyponatremia is caused by the inappropriate secretion of arginine vasopressin (AVP) and the excessive intake of hypotonic liquid accompanied by increased hyperthermia. Symptomatic, even deadly hyponatremia is seen more frequently in females, with the effects of oestrogen on arginine vasopressin believed to be the cause. Onset in such cases is acute, and treatment should be given to symptomatic patients as quickly as possible, with 3% saline administered when necessary. Reasons for acute kidney injury may include rhabdomyolysis, malign hypertension, and necrotizing vasculitis.