Morning sickness is the common queasiness that eases by mid-pregnancy while you still keep food and fluids down; hyperemesis gravidarum is relentless vomiting with dehydration and weight loss, per the NHS - thought to affect around 1 to 3 in 100 pregnancies and often needing hospital treatment.
The line is functional: cannot keep fluids down for 24 hours, little dark urine, dizziness on standing, or losing weight - same-day call to your midwife or doctor. HG is a medical condition with effective treatments, not weakness, and it tends to recur - a history belongs in every future pregnancy plan.
What to do
Common questions
What is morning sickness vs hyperemesis?
The difference is severity and consequence, not kind. Morning sickness: nausea with or without vomiting, very common, worst in the first trimester, usually easing by weeks 14 to 16 - miserable but manageable, and you can still keep food and fluids down overall. Hyperemesis gravidarum (HG), per the NHS: relentless nausea and vomiting that does not ease, inability to keep food or fluids down, dehydration, and weight loss - it is thought to affect around 1 to 3 in 100 pregnancies and often needs hospital treatment, including IV fluids and anti-sickness medication. The warning line is functional: if you cannot keep fluids down for 24 hours, are peeing little and dark, feel dizzy standing, or are losing weight, that is past normal morning sickness and needs a same-day call to your midwife or doctor - untreated HG is dangerous for mother and baby. Also worth knowing: HG is a medical condition, not weakness, effective treatments exist, and it tends to recur in later pregnancies so a history of it belongs in every future pregnancy plan. Pymander, a free AI doctor available 24/7 by text, can help you gauge where your symptoms sit.