Swelling and burning of half of the face may be caused by physiological factors or by diseases such as rosacea. 1. Physiological factors: In the case of emotional excitement, tension, etc., the blood flow rate of the face increases, and the swollen and hot face may appear. In places with cold temperatures and strong ultraviolet rays, the capillaries are abnormal, and half of the face may be red, swollen and hot. This is a normal phenomenon. 2. Pathological factors: Rosacea is a kind of chronic inflammation of the face, the patient may appear half of the face skin redness, capillary dilation, papules and other symptoms, and thus self-conscious face swelling hot. Patients with mumps may experience redness, swelling and pain on one side of the face. Patients should go to the hospital in time, after clarifying the cause of the disease, and then carry out the corresponding treatment.