Brushing teeth dry heaving may be associated with pharyngitis, personal constitution or improper selection of toothbrush and other reasons. 1. Pharyngitis: chronic pharyngitis mucosal erythema, congestion or follicular hyperplasia, resulting in pharyngeal mucosal sensitivity, toothpaste toothbrush stimulation of pharyngeal when brushing, pharyngeal and throat sensitivity, causing dry heaving. 2. Individual constitution: Due to individual differences in each person, the back of the pharynx has more nerve endings, when brushing teeth with the mouth open and stimulated by the toothbrush, especially the foam stimulation of the toothpaste, there are sensitive symptoms such as dry heaving, which is a normal physiological phenomenon. 3. Improper choice of toothbrush: toothbrush brush head is too large, the oral space is not enough, coupled with the foam of the toothpaste, the toothbrush touches the back of the palate, stimulation of the pharynx, the emergence of dry heaving, the use of smaller brush head toothbrushes, the amount of toothpaste to put a little less.