The most common is the initial stage of gastrointestinal flu, usually called the latent stage of acute gastroenteritis, when there are clinical symptoms such as weakness, nausea, anorexia, not wanting to eat, occasionally accompanied by fever, vomiting and other clinical manifestations. 2, weakness, not wanting to eat, often with clinical manifestations of hypoglycemia, when there is weakness, and sweating and other clinical conditions. The clinical symptoms are often due to insufficient blood supply to the large arteries, such as insufficient blood supply to the coronary arteries and cerebral arteries, and symptoms such as chest tightness, shortness of breath, precordial discomfort, and dizziness. The clinical manifestations of some rare diseases, such as anemia, tumor, tuberculosis, may also show such symptoms.