The swallowing process of a normal person is divided into five stages: pre-oral, oral preparation, oral, pharyngeal and esophageal. Pre-oral phase is to perceive things through vision and smell, and send things to the mouth with utensils; oral preparation phase is to open the patient’s mouth and keep things in the oral cavity; oral phase is to push things toward the pharynx; pharyngeal phase is when the soft palate is lifted up, closing the nasal passages, the vocal folds are closed, and the airway is closed to prevent aspiration and laryngeal penetration, and the pharyngeal peristalsis squeezes the food mass through the pharynx to move to the cricopharyngeal muscle, which is located at the upper part of esophagus, and the food mass can pass through it when relaxed; esophageal phase is when the esophagus generates a wave of peristaltic movements to push the food mass through the esophagus. The esophagus produces peristaltic waves during the esophageal phase to push the food mass through the esophagus and thus into the stomach. Clinical Functional Examination of Dysphagia: 1. Repeated Saliva Swallowing Test (RSST): It is a method to assess whether the swallowing reflex can induce swallowing function, which is as follows: (1) The examined person should, in principle, be in a sitting position, and adopt a relaxation position when he/she is lying on the bed. (2) The examiner will put the finger on the patient’s glottis and hyoid bone, let it try to repeatedly and quickly repeated swallowing, the glottis and hyoid bone with the swallowing movement, crossing the finger, moving forward and upward and then reset, confirming that this up and down movement, the moment of descent that is, the moment of completion of swallowing. (3) Observe the number of times the patient swallows and the degree of movement within 30 seconds. When the patient’s mouth is dry and he/she is unable to swallow, about 1ml of water can be injected on the tongue surface and then let him/her swallow. Three times in 30 seconds is sufficient for elderly patients. For patients who are unable to follow instructions due to impaired consciousness or cognitive impairment, the repeated saliva swallow test is difficult to perform, in which case a cold massage can be done in the mouth and pharynx to observe the swallowing and the time required for swallowing to be initiated. The swallowing process in a normal person is divided into five phases: pre-oral, oral preparatory, oral, pharyngeal and esophageal. Pre-oral phase is to perceive things through vision and smell, and send things to the mouth with utensils; oral preparation phase is to open the patient’s mouth and keep things in the oral cavity; oral phase is to push things toward the pharynx; pharyngeal phase is when the soft palate is lifted up, closing the nasal passages, the vocal folds are closed, and the airway is closed to prevent aspiration and laryngeal penetration, and the pharyngeal peristalsis squeezes the food mass through the pharynx to move to the cricopharyngeal muscle, which is located at the upper part of esophagus, and when it relaxes, the food mass can pass through; esophagus phase is the time to start swallowing; oesophageal phase is the time to relax, and the esophagus can pass through the esophagus. The peristaltic wave generated in the esophagus during the esophageal phase pushes the food mass to pass through the esophagus and thus enter the stomach. 2.Drinking water test The observation process is as follows: first let the patient drink 30ml of water as usual, then observe and record the time of drinking water, whether there is any choking and coughing, and the condition of drinking water, etc. Also record whether the patient will appear the following situations, such as slurping, containing drinking water, water out of the corners of the mouth, eating at the same time, to be reluctant to continue to drink, and drinking carefully. The drinking test can not only observe the patient’s drinking situation, but also can be used as a screening criterion for whether swallowing imaging examination can be performed.