There are many causes of morning sickness, including colds, gastrointestinal disorders, chronic laryngitis, and early pregnancy. If there is no fever, headache, dizziness, stomach pain, etc., and no abnormal physical discomfort, cold and gastrointestinal diseases can generally be excluded. If you do not brush your teeth in the morning but have a reaction of nausea and vomiting, it means that it is not chronic laryngitis either. If you have not had your period for more than a long time, have a normal sexual life and are not using contraception, then you should consider it to be pregnancy. In the early stages of pregnancy, the embryo grows and develops in the uterus, producing a large amount of HCG, the hormone that most easily stimulates vomiting, especially in the early morning hours.