Sudden dizziness, nausea and discomfort after physical labor may be caused by low blood sugar, insufficient blood supply to the brain, and long-term lack of exercise. 1. Hypoglycemia Physical labor will consume a lot of energy and water, especially glucose consumption. The brain mainly relies on glucose to provide energy, at this time, if you can not timely supply, it is easy to appear symptoms of hypoglycemia, such as dizziness, nausea, vomiting and so on. 2. Insufficient blood supply to the brain After a lot of physical labor, the blood in the body may be mainly distributed in the muscles, resulting in a drop in blood pressure, insufficient blood supply to the brain, the body will experience nausea, dizziness, vomiting symptoms. 3. Decline in cardiopulmonary function For the long-term lack of exercise, cardiopulmonary function decline, suddenly after a large number of physical labor, the heart function of blood supply is insufficient, it is easy to brain ischemia, oxygen deprivation, and then prone to dizziness, nausea, nausea and other symptoms. If the symptoms of dizziness and nausea occur frequently, it is recommended to consult a doctor in a timely manner and follow the doctor’s instructions for examination and treatment.