Common clinical manifestations of digitalis poisoning include gastrointestinal reactions and various cardiac arrhythmias, as well as neurological manifestations and visual changes. 1. Gastrointestinal reactions: generally mild, with poor appetite, nausea, vomiting, diarrhea and abdominal pain. 2.Cardiac arrhythmia: The sudden change of heart rhythm in the process of taking digitalis is an important basis for the diagnosis of digitalis poisoning. For example, the heart rate suddenly slows down or accelerates significantly, and changes from irregular to regular, or from regular to irregular with special regularity. The characteristic arrhythmias of digitalis intoxication are: multi-source ventricular premature beats in duplex rhythm, especially occurring on the basis of atrial fibrillation; atrial fibrillation with complete atrioventricular block and atrioventricular node rhythm; atrial fibrillation with accelerated junctional autonomic rhythm showing disturbing atrioventricular separation; atrial fibrillation with frequent junctional escape or short bouts of junctional rhythm; supraventricular tachycardia with atrioventricular block; bi-directional Junctional or ventricular tachycardia and dual tachycardia. Different degrees of sinus and atrioventricular block caused by digitalis are also common. Supraventricular tachycardia with atrioventricular block during the application of digitalis is a characteristic manifestation of digitalis toxicity. 3. Neurological manifestations: headache, insomnia, depression, vertigo, and even confusion may occur. 4. Visual changes: yellow or green vision and diplopia may appear.