Morning Sickness: 8 Common Causes & What to Do

March 2023

Morning sickness is very common in the first weeks of pregnancy, but it can also occur outside of pregnancy and can even happen to men.

Most of the time, morning sickness that is not related to pregnancy happens in people who do not sleep well or who have gone a long time without eating. These cases can be easily resolved. However, it's important to note that morning sickness can also be the first sign of several health problems such as acid reflux, kidney stones, or stomach ulcers.

If nausea does not improve within a few minutes, or if it happens frequently, it is best to consult a gastroenterologist to identify the cause and start appropriate treatment.

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 Common causes of morning sickness include:

1. Pregnancy

Morning sickness is one of the classic early symptoms of pregnancy. Morning sickness that occurs to fertile women, particularly between the ages of 20 and 30, usually occurs due to pregnancy.

Pregnancy-related nausea happens due to hormonal changes in the woman's body. It usually appears by the 4th week of pregnancy and can occur several times throughout the day (not just the morning!).

What to do: Confirm whether you are pregnant or not with an over-the-counter pregnancy test or by consulting your gynecologist. Check out our tips on when to take a home pregnancy test and how to perform one.

2. Sleep disturbances

Fatigue can also induce morning sickness. Nausea normally appears in people who undergo changes to their sleep patterns (e.g. with jet lag or insomnia). With lack of sleep, the body has inadequate time to repair itself and this can cause a dysfunction in hormonal production resulting in morning skickness.

What to do: You should try to sleep 7 to 8 hours a night to make sure your body has enough time to repair itself during sleep. If you have jet lag, adjust to your new time zone by trying to rest on the first day and avoiding any strenuous activities.

3. Fasting

People who spend too long without eating, especially more than 10 hours, may feel morning sickness due to a decrease in blood sugar levels.

Other symptoms that can emerge with low blood sugars include dizziness, weakness, and chills.

What to do: To prevent morning sckness, avoid fasting for more than 8 to 10 hours. Try having a light snack before bed, such as plain yogurt or jello. 

4. Hangover

A hangover, which happens after excessive intake of alcohol, is another common cause of morning sickness.

When too much alcohol is consumed, hydration levels decrease, as well as the amount of glucose in the blood, and this results in symptoms such as nausea and vomiting, headache, and sensitivity to light. 

What to do: To avoid morning sickness from hangovers, tit is important to increase hydration levels by drinking a lot of water throughout the day, and maintain glucose levels by eating fruit. Some people may benefit from having a coffee without sugar. Read about ways to cure a hangover at home. 

5. Heartburn

Heartburn, or acid reflux, happens when acid from the stomach backs-up into the esophagus, causing symptoms like burning, bloating, and nausea.

Even though nausea caused by heartburn can appear at any time of the day, it occurs more frequently in the early morning. This is because the stomach has been empty for a long time and the lying position from sleeping facilitates a back-up of acid into the esophagus.

What to do: You can reduce heartburn by sleeping in an elevated position to prevent stomach acid from reaching the esophagus. In addition, a light snack before bed can also help decrease the amount of time the stomach is empty, thus reducing acidity. 

7. Stomach ulcer

Nausea is a common symptom for people with stomach ulcers, and although it can happen at any time of the day, it occurs more frequently in the morning. This is due to the build-up of acid that occurs overnight from having an empty stomach. This built-up acid can create and worsen an ulcer, causing more inflammation and additional nausea and vomiting.  

What to do: Stomach ulcers can be treated with a diet based around natural, wholegrain foods. An assessment with the gastroenterologist is recommended, and medication may be prescribed (e.g. antacid medication).

8. Ear inflammation

The vestibular system, a structure located in the inner ear, is responsible for balance. Inflammation to this area can cause imbalance, which may lead to nausea and vomiting.

Other symptoms that can appear are pain, itchiness, reduced hearing, and discharge. 

What to do: If you suspect you have ear inflammation, a consult with an otolaryngoligist is recommended, He or she will confirm a diagnosis and prescribe treatment, which may include antibiotics or anti-inflammatories.

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Written and updated by Daisy Oliveira - Registered Nurse, on March of 2023.


  • NHS. Vomiting and morning sickness in pregnancy. Available on: <>. Access in 19 May 2020
  • MINISTÉRIO DA SAÚDE. Refluxo gastroesofágico. Available on: <>. Access in 03 Feb 2020
Our team made up of medical doctors and health professionals from various fields such as nursing, nutrition, physiotherapy, clinical analysis and pharmacy.