Severe pregnancy vomiting can be caused by three things.
Changes in the body: High levels of HCG in the body reduce the acidity in the stomach, leading to slower peristalsis and impaired gastric emptying. In early pregnancy, the body’s HCG level rises, causing nausea and vomiting. During pregnancy, the body’s sex hormones also increase, and increased levels of oestradiol can also exacerbate the symptoms of nausea and vomiting. Progesterone acts on the gastrointestinal tract and can inhibit the action of smooth muscle, slowing down peristalsis, reducing gastric emptying, decreasing appetite and distending the stomach, making it easy to experience pregnancy vomiting.
Diet and lifestyle: Nowadays, many women still go to work as usual despite being pregnant. With more work, they often neglect their diet and work and rest, which can also lead to vomiting and must ensure adequate rest and intake of sufficient nutrition.
Psychological effects: pregnancy is prone to negative emotions, which can affect the changes in endocrine hormone levels in the body and nausea and vomiting can be more intense.