There are many side effects of atropine, such as dry mouth, dilated pupils, difficulty in urinating, and central arousal. Atropine belongs to a kind of anticholinergic drug, which has the effect of relieving smooth muscle spasm and improving microcirculation. In clinical practice, this drug is mainly used to relieve visceral colic, such as pain caused by gastrointestinal spasm, renal colic, biliary colic, and gastric and duodenal ulcers. It is also used to treat sinus bradycardia or atrioventricular block. Common side effects of this medication include constipation, decreased sweating, dryness of the mouth and throat, blurred vision, flushing of the skin, difficulty urinating, low gastrointestinal drive, and gastroesophageal reflux. Some patients may also experience increased intraocular pressure, allergic rash or vesicular rash. When patients use its eye drops, it may also cause local allergic reactions and drug contact blepharoconjunctivitis. The drug should be used under the guidance of a professional physician, and should not be used on its own. When patients experience serious side effects with atropine, prompt medical attention is recommended.