First of all, don't eat too much at night, especially when you go to a big meal, spicy food, etc., too much is easy to indigestion, resulting in stomachache, and the next day is bound to be stomach upset, nausea and vomiting.
We should make sure that we have about eight hours of sleep every day. Don't stay up late all the time. It's too harmful to our health.
In the morning, when brushing your teeth, don't stick your toothbrush very inside. It will irritate your throat and make you sick and retch.
It may be chronic pharyngitis, which is the most common cause of nausea and retching. It's better to go to the hospital.
Gastritis, many stomach diseases are a lot of stomach acid, it is easy to cause nausea and retching.
Many pregnant women feel sick and retch when they brush their teeth in the morning.
When squeezing toothpastes, you should use appropriate amount. Don't squeeze too much. Too much will definitely cause oral discomfort.
There are calculus in the teeth or frequent bleeding of teeth, which will cause peculiar smell in the mouth, and it is easy to be disgusted.