Morning sickness and pregnancy nausea explained

Why it happens

The exact cause of pregnancy sickness is not fully understood, but it is closely linked to the hormone changes of early pregnancy, especially a hormone made by the developing placenta. Levels of this hormone rise quickly in the first weeks, which is roughly when sickness is at its worst. This is why it is often seen as a normal sign that the pregnancy is developing. Sickness tends to be more common and more severe in first pregnancies and in twin or multiple pregnancies, where hormone levels are higher. A heightened sense of smell is common too, so everyday odours like cooking, coffee or perfume can suddenly trigger nausea. It is not caused by anything the pregnant person has done wrong.

How long it usually lasts

For most people, pregnancy sickness begins in the first few weeks, often around week six, reaches its peak around weeks nine to eleven, and eases by around weeks 16 to 20. A smaller number continue to feel sick for longer, and occasionally it lasts the whole pregnancy. Symptoms range from mild queasiness to being sick several times a day. Ordinary morning sickness, even when miserable, still allows you to keep down some food and fluids over the day. If it settles into a predictable pattern and you can stay hydrated and nourished, it is usually the normal kind. Knowing that it is typically time-limited can be reassuring when you are in the middle of it.

Self-help that can ease it

Several simple measures help many people. Eating little and often, rather than large meals, keeps the stomach from being too empty or too full. Plain, bland foods such as toast, crackers or dry biscuits are often better tolerated, and having a dry snack before getting up can take the edge off. Cold foods may smell less and be easier than hot meals. Sipping fluids regularly in small amounts helps prevent dehydration; some find cold, fizzy or sour drinks easier. Ginger, as ginger biscuits or ginger tea, eases nausea for some people. Rest helps, as tiredness can make sickness worse. Avoiding known triggers — certain smells or foods — and getting fresh air can also make a real difference.

When to get medical help

Most pregnancy sickness needs no treatment, but you should contact your midwife or GP if it is severe or you are worried. Seek advice if you cannot keep any food or fluids down, are being sick many times a day, feel very weak or dizzy, are passing dark urine or very little urine, or are losing weight. These can be signs of dehydration or of hyperemesis gravidarum, the severe form of pregnancy sickness that may need hospital treatment with fluids and anti-sickness medicine. Also seek advice for tummy pain, a high temperature, or vomiting blood. There are safe anti-sickness medicines a clinician can prescribe if needed, so you do not have to simply endure severe symptoms.

Looking after yourself and getting support

Even the ordinary form of morning sickness can wear you down and affect work, family life and mood, and it is fine to acknowledge that. Be kind to yourself: rest when you can, accept help with cooking and chores, and choose whatever foods you can face, even if your diet is not perfect for a few weeks — appetite and variety usually return. Keep up your pregnancy vitamins if you can, though taking them with food or at a different time of day may help if they worsen nausea. If sickness is affecting your wellbeing or you feel low, mention it at your antenatal appointments. Support from a midwife, and organisations focused on pregnancy sickness, can help you cope.