Sudden spitting and inability to swallow may be caused by psychological factors, acute epiglottis cyst, esophageal cancer, pharyngeal cancer and so on. 1. Psychological factors: sudden tension and anxiety in the heart, resulting in vegetative nerve disorder, leading to sudden spitting and feeling of not being able to swallow. 2. Acute epiglottis cyst: chronic inflammation or mechanical stimulation for a long time causes blockage of epiglottis mucous gland ducts, which leads to retention of secretion and formation of cysts, and the cysts are bigger and block the pharynx, which leads to sudden vomiting and inability to swallow. 3. Esophageal cancer: malignant tumor occurs in the esophagus, and the persistent enlargement of the tumor will cause difficulty in swallowing and sudden inability to spit and swallow. 4. Pharyngeal cancer: a malignant tumor in the pharynx blocking the pharynx can also lead to swallowing obstruction and sudden spitting and gagging. It is recommended to seek medical treatment as soon as possible and standardize the treatment under the guidance of physicians.