Head swelling at noon may be related to brain fatigue, or may be caused by low blood sugar reaction, insufficient blood supply to the brain and other reasons. 1. Brain fatigue: In the morning if the work is too busy, the work needs to deal with more affairs, the whole morning for a long time for frequent mental labor, to noon easily caused by brain fatigue, may cause head swelling at noon, but also may be accompanied by dizziness, body fatigue and other symptoms. 2. Hypoglycemic reaction: some young people may often skip breakfast in the morning, and at noon, due to a long period of failure to eat, it is easy to cause hypoglycemic reaction, resulting in insufficient blood supply and oxygenation of the brain tissues, which may lead to swelling of the head from noon onwards, and may be accompanied by panic, trembling of the hands, sweating and other manifestations. 3. Insufficient blood supply to the brain: If you eat too much lunch at noon, after eating, the blood in the body will gather to the gastrointestinal tract, participate in the digestion and absorption of gastrointestinal food, which is likely to cause a relative lack of blood supply to the brain, may cause head swelling at noon, accompanied by dizziness, weakness and other manifestations. Head swelling at noon, may also be related to other factors, if the symptoms are more obvious, or the presence of other discomfort, should be as early as possible to consult a doctor, after diagnosis of the cause of the disease, under the guidance of a professional doctor for treatment.