Oral and labial herpes (facial herpes) is the most common type of herpes simplex. Common symptoms: flushing of the mouth and lips, appearance at the corners of the mouth and around the nose, numbness and tingling around the mouth and lips, blistering in the mouth, and blisters on the hands and feet. It is often characterized by initial localized burning, itching and flushing, followed by the appearance of dense clusters or groups of pinhead-sized blisters, which are smaller and more clustered than the primary type of blisters, rupture and vesicles, ooze, and gradually dry and crust. The cause of the disease is really related to infection with herpes simplex virus, immune system decline, and environmental factors. 1, virus infection Oral lip herpes belongs to a viral skin disease, is caused by herpes simplex virus infection, normal people also often occur, mostly due to fever or the body at a certain stage of excessive fatigue, excessive physical exertion, the body of various nutrients supply is insufficient, resulting in a decline in immunity. 2, immune system decline When the patient has a fever, the body resistance is low, fever, saliva secretion is reduced, the flushing effect of the oral cavity is weakened, food residues are easy to stay in the mouth, but also for microbial growth and reproduction to create good conditions, fever, the oral cavity often becomes the comfort zone for bacterial growth. Such a time, the virus often take advantage of the situation, in the skin around the mouth and lips, gums and other seizures. 3, environmental factors summer temperature is too high, the body’s metabolism accelerates, nutrient consumption increases, and high temperatures often cause a decrease in appetite, lack of sleep, resulting in a lack of protein, vitamins, electrolytes and other nutrients in the body, so that immunity is reduced.