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What causes morning sickness?

Feeling nauseous during early pregnancy is very common, but have you ever wondered what causes morning sickness and why it affects some of us more than others? In this post, we’re going to take a closer look at pregnancy nausea, as well as some tips for relieving discomfort. Read on to find out more…

What is morning sickness?

Morning sickness is the name for nausea experienced during pregnancy. The name morning sickness is a bit misleading as you can feel nauseous at any time of the day or night. It’s a very common symptom of early pregnancy and is estimated to occur in seven out of ten pregnancies.

When does morning sickness start? 

Morning sickness typically begins in early pregnancy. Alongside a missed period, sore breasts or tiredness it’s often one of the first signs of pregnancy. While many people won’t experience any symptoms at all during the first few weeks of pregnancy, morning sickness can happen at any time during the first twelve weeks.

How long does morning sickness last?

The good news is that most people don’t feel sick for their entire pregnancies. Typically, morning sickness is at its worst during the first three months and tends to go away around weeks 16-20.

Morning sickness causes 

The root causes of morning sickness is widely believed to be hormonal changes happening in the first twelve weeks of pregnancy. Specifically, it’s believed to be rising blood levels of a hormone called HCG (human chorionic gonadotropin) that is responsible for making us feel nauseous. 

Not everyone experiences nausea during pregnancy, and there are some factors that can make us more likely to experience morning sickness such as:

  • Having morning sickness in a previous pregnancy
  • Expecting more than one baby
  • Obesity
  • Stress
  • Suffering from migraine headaches
  • A family history of morning sickness
  • Susceptible to motion sickness (such as getting car sick or sea sick)
  • It’s your first pregnancy
  • If you’ve been sick when taking birth control containing estrogen

What does morning sickness feel like?

Morning sickness varies from person-to-person, but has been described as similar to being travel sick, or having a hangover. There is also a severe type of morning sickness called hyperemesis gravidarum, this affects around two out of one hundred pregnant women. 

It’s important to be mindful of dehydration, which can happen if you’re frequently vomiting and aren’t managing to keep fluids down. Contact your healthcare professional if you’re vomiting and experience any of the following symptoms:

  • Have dark-colored urine or haven’t peed in more than 8 hours
  • Are unable to keep food or fluid down for more than 24 hours
  • Are vomiting blood
  • Feel extremely weak, dizzy or faint when you stand up
  • Have a high temperature
  • Have lost weight
  • Have abdominal pain

Relief for morning sickness 

In most cases, you can manage symptoms yourself at home, by trying the following things:

  • Eating crackers or dry toast before getting out of bed in the morning
  • Eat little and often 
  • Avoid preparing food if the smell makes you feel nauseous 
  • Avoid foods that make you feel unwell
  • Try eating plain carbohydrate-based food such as pasta, rice or cereal bars
  • Drink plenty of fluids 
  • Try eating ginger, there is some evidence to suggest it can help with nausea

If your morning sickness is severe, you may be recommended a short course of anti-sickness medication. If you’re suffering from morning sickness, talk to your doctor or midwife about your full list of treatment options.

What medications can I take at home during pregnancy?

It’s often difficult to know what medication is and isn’t safe to take at home during pregnancy. Since all our medical histories and our pregnancies are different, the best thing you can do is check with a healthcare professional before taking any medicine. 

Plan your pregnancy with Natural Cycles


Thanks for reading up on the causes of morning sickness, we hope you learned something new. At Natural Cycles we’re dedicated to creating better awareness around reproductive health, and our technology is designed to adapt to you, as your fertility partner, to help you plan or prevent pregnancy as you need. An FDA Cleared medical device, Natural Cycles is the first of its kind, learn about how Natural Cycles works to find out more.

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Written By

Jennifer Gray

A writer with a passion for women’s health, Jennifer Gray has years of experience writing about various reproductive health topics including birth control, planning pregnancy, women’s anatomy, and so much more.

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Scientifically Reviewed

Jack Pearson

Dr. Jack Pearson is Natural Cycles’ in-house medical expert. With 10+ years of experience working in the field of fertility, he dedicates the majority of his time to conducting groundbreaking research within the field of women's health.

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