Hello. Normal low blood pressure is 60-90mmhg. If the low pressure is lower than 60mmhg, it is hypotension and is abnormal. Possible reasons include physical weakness, insufficient blood volume, dehydration and fluid loss, massive blood loss, cardiac insufficiency, shock caused by various reasons, etc. If it is a constitutional condition, you can drink more water, eat a salty diet, and use traditional Chinese medicine such as Shengmai Yin to adjust your blood pressure.