Causes & triggers

The cause of morning sickness lies primarily in the hormonal changes in the body. In early pregnancy, levels of the pregnancy hormone hCG (human chorionic gonadotropin) and the messenger substance GDF15 (growth differentiation factor 15) rise sharply. These hormones act directly on certain areas of the brain that control nausea, appetite, and vomiting. The body must first adapt to these new signals, which explains the basic development of nausea.

External and physical factors that increase existing hormonal sensitivity act as triggers. These include smells, certain foods, an empty or overfull stomach, low blood sugar, fatigue, or stress. In later stages of pregnancy, mechanical factors can also come into play, such as the pressure of the growing uterus on the stomach and digestive organs. These triggers do not cause nausea themselves, but they can significantly increase it or cause it to recur.

What helps to avoid typical triggers of morning sickness?

• Eat regularly: Small, frequent meals help to avoid an empty stomach and sharp fluctuations in blood sugar levels.
• Avoid extremes: Strongly spiced and very sweet foods can increase nausea and should be avoided if possible.
• Eat a balanced diet: A diet rich in protein and carbohydrates but low in fat and acid is often better tolerated.
• Avoid strong smells: Intense cooking, perfume, or cleaning smells can trigger nausea.
• Recognize individual triggers: Consciously avoid certain foods or flavors if they cause discomfort.
• Do not overload your stomach: Very large or hard-to-digest meals can increase nausea.
• Drink enough fluids: It is best to drink small sips throughout the day.
• Plan rest breaks: Fatigue and overexertion can increase nausea.
• Reduce stress: Emotional stress can intensify physical symptoms.
• Stay upright after eating: This aids digestion and can prevent heartburn.
• Get some fresh air: Regular ventilation or short walks can be helpful.

These measures cannot influence hormonal causes, but they help many pregnant women to reduce typical triggers and make everyday life more pleasant.

Although nausea during pregnancy is usually caused by hormones, there are other conditions that should be ruled out before assuming it is typical morning sickness.

These include, above all, gastrointestinal infections, which usually begin suddenly and are often accompanied by diarrhea, fever, or abdominal pain. Food poisoning or intolerances can also cause nausea, often in connection with a meal.

Stomach disorders such as reflux or gastritis should also be considered, especially if heartburn or burning pain in the upper abdomen are the main symptoms. Urinary tract infections can also cause nausea during pregnancy and are often accompanied by discomfort when urinating or lower abdominal pain.

Less common are metabolic causes, such as thyroid disorders, which can also cause symptoms such as heart palpitations, weight changes, or severe fatigue. Hyperemesis gravidarum, a severe form of morning sickness with persistent vomiting, dehydration, and weight loss, must also be ruled out and requires medical treatment.

A medical examination is particularly important if the nausea is unusually severe, occurs for the first time, worsens significantly, or is accompanied by other symptoms.