Dizziness after eating crabs has the following reasons: 1, consider eating crabs after allergy caused by, for minor allergies, people can appear dizziness, panic and weakness and other symptoms. If severe allergy occurs, the patient may also experience hypotensive shock. It is recommended that especially those who are allergic to seafood should pay attention to the allergic reaction after eating crabs. 2. Considering that more crabs are eaten at one time, crabs belong to the food with high protein content, and the stomach needs a large amount of blood to promote the digestion of proteins, which will reflexively cause the insufficient blood supply to the brain, and the patient may experience dizziness and weakness. Dizziness and fatigue may occur. 3. It is also considered to be due to the coldness of crabs, after eating crabs, people may have diarrhea, and dizziness caused by blood volume insufficiency, according to the accompanying symptoms of the initial diagnosis.