The following factors should be taken into account when patients experience dizziness and nausea after eating crabs: 1. Consider that the crabs consumed are not fresh or cooked after being placed for too long, which can easily lead to dizziness and nausea. 2. Consider that the crab itself is caused by its properties, because crabs are cold food, and if too much is eaten at one time, it can lead to cold stimulation of the spleen and stomach, which can easily lead to dizziness and nausea. 3. 3. Consider that eating crab may have caused an allergic reaction, so patients should pay attention to whether there is a subcutaneous or oral mucosal rash, and if so, give anti-allergy treatment in a timely manner. In addition, the patient should also have his blood pressure and heart rate measured, and the patient can also drink more water to promote the excretion of the ingested crab out of the body.