Dizziness And Lightheadedness While Standing. What Could It Be?
You are having a condition known as Orthostatic Hypotension. In this, the blood pressure transiently comes down below normal on rising up from sitting/lying down position suddenly. This occurs due to pooling of blood in legs when we suddenly get up. This leads to transient reduction in the blood supply to brain and therefore, lightheadedness, dizzyness and fainting.
Its a common condition can be normally seen even in healthy people. If its frequent and occurs each time and also after sitting for short periods, then its a concern.
In your case it occurs after sitting for long periods of time. So its a normal phenomenon.
How to avoid or prevent ?
1. When getting after sitting up for long times, stretch the legs and move the legs for few seconds to facilitate blood circulation. Rise slowly.
2. Maintain good water intake - 3 - 4 litres/day
3. Increase your salt intake.
This should help.
There is no need for further evaluation if you become better
Hope this answers your query.
Thanks and Regards
Dr Kiran