Check your blood pressure, please.
“Blood pressure decreases when blood vessels relax or lose their ability to constrict. If there is less fluid in the body, the circulating blood volume is decreased and blood pressure drops. Normal blood pressure range is usually 100/60 to 140/90. While some people will not experience any warning signals, drops in blood pressure below 100/60 may result in dizziness, lightheadedness, or weakness. If severe, hypotension can lead to fainting and/or falling. Individuals have also used terms such as giddiness, sleepiness, tiredness, and mental or visual blurring to describe what has actually turned out to be low blood pressure.
These sensations will often intensify upon standing or after walking. Although any time...”