Usually, there are more reasons for nighttime attacks of urticaria, usually due to contact with allergens and fluctuating hormone levels. 1. Contact with allergens: urticaria is mainly caused by allergic reactions, may live in an environment where there are allergens, such as bed sheets with mites, sensitive to the smell of furniture paint, etc. can cause urticaria. It is recommended that patients isolate allergens in time and avoid spicy and irritating foods in their diet. 2. Hormone level fluctuations: hives usually worsen at night, may be related to the human adrenocorticotropic hormone level is lower at night. It is recommended to use anti-allergy medication under the guidance of a doctor, such as loratadine and cetirizine. Patients suffering from urticaria are advised to go to a specialized hospital for the next examination and treatment under the guidance of a doctor.