Hyperemesis gravidarum (HG) affects 0.3-3.6% of pregnant women and can have a major impact on physical and mental health. Despite clear guidance on safe and effective treatments, many women with HG receive limited treatment. Intractable vomiting can result in nutrient deficiencies, electrolyte disturbance and dehydration. For affected women the serious medical consequences associated with HG include Wernicke’s encephalopathy secondary to thiamine deficiency, hyponatraemia, hypokalaemia and venous thromboembolism. There is an association with small for gestational age babies, and the children of HG pregnancies have been reported to have increased rates of neurodevelopmental disorders. This talk will review the current literature relating to the aetiology of HG, maternal and child complications of the disorder and current guidelines and management strategies.