I have normal blood pressure during the day and very low blood pressure at night. what can i do to put it normal?

BP dip: Our blood pressures normally dip at night. This is a normal cycle. BP also declines after eating. This is due to blood pooling in our intestinal vessels for digestion and absorption. Be careful. Don't overeat in the evening. Perhaps you need a bit more salt. Measure BP lying then standing a few days in a row -- both am and pm times and before bed. This will provide data for your doctor.

It depends: Know that it's normal for your blood pressure to decrease at night. But two things that matter to determine if this is worrisome, is how low is low and do you have any symptoms like lightheadedness, dizziness, and/or weakness when your blood pressure is "low". This information is very helpful for better counseling you.