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When Does Morning Sickness Start and End?

Morning sickness usually kicks in around week 6 and eases off by the second trimester. The usual timeline, what causes it, and the signs that mean you should call your provider.

Pregnancy Tools Editorial TeamPublished 2026-04-30Updated 2026-06-242 min read

The name is a bit of a lie. "Morning sickness", the nausea and sometimes vomiting of early pregnancy, can hit at any hour, morning, noon, or 9pm on the sofa. Knowing the usual arc helps you sort what is normal from what is worth a call.

When it usually starts

For most people the queasiness begins around week 6, occasionally as early as week 4 or 5, soon after hCG starts climbing. The pregnancy week calculator tells you which week you are in. It is one of the earliest and most common pregnancy symptoms, though plenty of people skip it entirely.

When it peaks and eases

Things often feel worst around weeks 9 to 11, when hCG peaks, and then ease for many people by weeks 12 to 16 as the second trimester arrives. A smaller group stays nauseous longer, sometimes the whole way through. The pregnancy week guide sets out what to expect.

Why it happens

Nobody has fully pinned down the cause. The leading suspects are the surge in pregnancy hormones, especially hCG and oestrogen, paired with a suddenly sharper sense of smell. In most cases it is just a normal part of early pregnancy, not a sign that something is wrong.

Taking the edge off mild symptoms

When to call your provider

Get advice if you cannot keep fluids or food down, you are losing weight, you feel dizzy, or you are barely passing urine. That combination can mean hyperemesis gravidarum, a severe form that needs treatment. Keep your timeline handy with the due date calculator and raise symptoms at every visit.

FAQ

When does morning sickness usually start?

Most often around week 6, sometimes as early as week 4 or 5, just after hCG starts to rise.

When does morning sickness end?

For many it eases by weeks 12 to 16 as the second trimester begins, though some people carry it longer.

When should I worry about morning sickness?

If you cannot keep fluids down, are losing weight, feel dizzy, or are passing little urine, call your provider. It may be hyperemesis gravidarum, which needs treatment.

Editorial review and disclaimer

A quick note: this article is general information for planning and learning, not a substitute for professional advice, diagnosis, or treatment. Anything specific to your own pregnancy is worth checking with your doctor or midwife.

References:

Written and checked by the Pregnancy Tools editorial team · Last reviewed 2026-06-24 · About a 2-minute read · See About us