BP low, how much normal?

Normal low pressure value is generally above 60mmHg, below 90mmHg, the most accurate should be usually not sick, calm mood, no low pressure value measured after exercise. Sometimes the weather will also affect the low pressure value, such as cold weather blood pressure will be slightly increased, because the blood vessels are contracted after cold, if the weather is hot, the blood vessels will expand accordingly causing blood pressure to increase a little. When people get up in the morning, their blood pressure should be the lowest in the day. In the evening, their blood pressure will reach the highest value in the day. As long as they fluctuate within the normal range, there will be no problem. After their blood pressure is low, they should pay attention to rest. If the low pressure is higher than 110mmHg, they should pay attention to diseases such as cerebral hemorrhage. If it is lower than 60mmHg, it will also cause insufficient blood supply to show fainting and shock.