Why does hives only rise late at night?

Urticaria only late at night from the causes of changes in human hormone levels at night, temperature changes at night, increased exposure to allergens at night, vagus nerve excitation at night, more focused attention at night, sleep environment is relatively closed. 1. Changes in hormone levels at night In the night, the hormone levels such as corticosteroids in the body are relatively low, and changes in hormone levels may lead to an imbalance in the regulation of the immune system, which is more likely to induce urticaria. 2. Changes in body temperature at night During sleep, there may be certain fluctuations in body temperature, and changes in temperature sometimes stimulate the skin, causing urticaria attacks. 3. Increased exposure to allergens at night, such as dust mites and pillow towels on the bed, are in closer contact with the human body at night, which may lead to allergic reactions and trigger urticaria.4. Night vagus nerve excitation is relatively increased at night, which may affect some physiological functions of the body, including susceptibility to allergic reactions. 5. Night attention is more concentrated during the day, people's attention is more dispersed, may not care about mild itching and other symptoms, and at night, attention is more focused on the body's feelings, more likely to detect the onset of urticaria. 6. Sleep environment is relatively closed. The environment in which you sleep at night is relatively closed, and the air circulation is relatively poor, which may also increase the risk of urticaria attacks.