The causes of sudden vertigo resulting in lower blood pressure are as follows: 1. vertigo caused by low blood pressure is related to ischemia in the inner ear and brain; 2. vertigo induced by low blood pressure due to arrhythmia and cardiac insufficiency; 3. vertigo can be induced by anemia secondary to dyspepsia, peptic ulcer, gastrointestinal bleeding and chronic inflammatory diseases; 4. vertigo caused by hypertonic dehydration and allergy resulting in lower blood volume and lower blood pressure; 5. vertigo can be induced by diseases that lead to lower blood pressure and blood volume.