Hives, hives at night can be caused by a variety of reasons, generally considered with food allergies, physical factors, insect bites, mental factors, endocrine changes and so on. 1. Food allergy: people and people’s physique is different, some people eat some beef and mutton, seafood, lemon, mango and other foods can occur after the occurrence of urticaria. 2. Physical factors: when the human body is allergic to underwear and other materials, or contact with some pollen, dust mites and other factors can lead to the occurrence of urticaria; can also be seen in friction, pressure, cold, heat, sunlight exposure and other factors. 3. Insect bites: when the human body is mosquito bites, insect bites, poisonous caterpillar stimulation and other factors, can lead to the occurrence of papular urticaria. 4. Mental factors: when the human body is subjected to violent mood swings, nervousness, depression and other factors, can lead to the occurrence of urticaria. 5. Endocrine changes: when the human body suffers from endocrine disorders such as hyperthyroidism can occur hives. Need to go to the hospital, under the guidance of the doctor to choose reasonable drugs and methods of treatment, they can not be randomly use drugs.