
Pregnancy is an exciting and transformative time in a person’s life. However, it often comes with a host of symptoms, one of the most common being vomiting. Understanding why vomiting occurs during pregnancy can help expectant mothers manage their symptoms better and seek appropriate care when necessary.
Understanding morning sickness
Vomiting during pregnancy is most commonly associated with morning sickness, which affects about 70 percent of pregnant women and other people. Despite its name, morning sickness can occur at any time of the day or night. The exact cause is not known, but several factors contribute to this condition.

Hormonal changes
The primary reason for vomiting during pregnancy is the rapid increase in hormones, particularly human chorionic gonadotropin (hCG) and estrogen. These hormones are crucial for maintaining the pregnancy but can also cause nausea and vomiting. hCG levels rise significantly during the first trimester, peaking around the 9th to 11th week. This increase correlates with the timing and intensity of morning sickness.
Sensitivity to smells
Pregnant people often develop a heightened sense of smell, known as hyperosmia. This increased sensitivity can trigger nausea and vomiting. Foods, perfumes and even common household odors can become overwhelming and lead to episodes of vomiting.
Gastrointestinal changes
During pregnancy, the gastrointestinal tract undergoes several changes. The muscles of the digestive system, including the stomach, relax due to increased progesterone levels. This relaxation can slow down digestion, leading to nausea and vomiting. Additionally, the growing uterus can put pressure on the stomach and intestines, contributing to these symptoms.
Psychological factors
Stress and anxiety are common during pregnancy and can exacerbate nausea and vomiting. The emotional changes and physical discomfort of pregnancy can create a cycle where anxiety leads to more severe symptoms, which in turn