Urticaria is a temporary exudation of blood plasma from the dermal blood vessels and manifests itself as a temporary, itchy, windy mass. Urticaria is divided into acute and chronic urticaria according to its course. If symptoms last longer than 6 weeks, it is defined as chronic urticaria, and most patients with chronic urticaria can have their symptoms disappear within 2 years. The etiology is complex and includes many endogenous and exogenous factors. Patients with chronic urticaria have an increased rate of positive thyroid autoantibodies; in children the incidence of abdominal disease is increased and appropriate investigations are recommended. If the urticarial lesions last longer than 24 hours, it may be urticarial vasculitis, the diagnosis of which requires skin biopsy and related investigations. Find the cause and remove it (factors such as food, infection and medication). Treatment is mainly oral antihistamines. First-generation antihistamines include chlorpheniramine, deslorpromazine, cyproheptadine, ketotifen, etc. They are taken 2-3 times a day and often have side effects such as drowsiness, dizziness and dry mouth; they are used with caution by drivers and people working at height; they are used with caution in patients with glaucoma and prostate hypertrophy. Second-generation antihistamines such as cetirizine, levocetirizine, loratadine, desloratadine, imipramine, etc., are taken once daily and have no or less drowsiness and other side effects, but there are individual differences, and patients should also be aware that these drugs are commonly used for treatment. Generally, the medication needs to be administered on a regular basis, and can be taken intermittently according to symptoms. Many patients have diurnal variations in symptoms, and the daily dosing time can be adjusted.