Morning sickness and hyperemesis gravidarum: causes, symptoms and management

Morning sickness, medically known as nausea and vomiting of pregnancy (NVP), affects up to 70‑80% of expectant mothers, typically beginning between weeks 4‑9 of gestation and often resolving by the second trimester. Hormonal changes drive the condition, with rapid rises in human chorionic gonadotropin (hCG), estrogen, progesterone and the placenta‑derived hormone GDF15 all implicated in triggering nausea, altered stomach acidity and slowed gastric emptying.

A small proportion of women (1‑3%) develop hyperemesis gravidarum, a severe form marked by persistent vomiting, weight loss of more than 5% of pre‑pregnancy weight, dehydration and electrolyte imbalance. Symptoms may include frequent vomiting, excessive salivation, dizziness, headaches and constipation. Medical treatment is required when dehydration or significant weight loss occurs, while milder cases can be managed with dietary adjustments, small frequent meals, ginger, vitamin B6 and adequate hydration.