What are the causes of morning sickness?

Morning sickness generally occurs in about 42 days after pregnancy, causing the cause of morning sickness, generally due to the rapid increase of human chorionic gonadotropin in the body, and the increase of estrogen in the body, causing gastrointestinal dysfunction in the body, causing nausea and vomiting, picky eating anorexia, weakness, dizziness, lethargy, mental tension, anxiety, etc. This situation requires drinking more boiled water, eating more vegetables and fruits, eating more light food that you like, with the increase of pregnancy time, symptoms will slowly disappear. Generally, symptoms will disappear naturally three months ago.