It is a bit more complicated than that but here’s a pretty obvious one, do you get more sleepy lying down or sitting on a chair or standing up?

Oh, also read this

Records show that diastolic pressure is about 55mm/Hg lower when taking blood pressure lying down vs. sitting.

https://www.belmarrahealth.com/blood-pressure-differences-wh...

Citing an online supplement store that says "records show" with no indication of where that data comes from isn't really the best source.

Perhaps more relevant would be the diagnostic criteria for orthostatic hypotension, a condition that most people don't have: https://www.aafp.org/afp/2011/0901/p527.html

> Orthostatic hypotension is defined as a decrease in systolic blood pressure of 20 mm Hg or a decrease in diastolic blood pressure of 10 mm Hg within three minutes of standing when compared with blood pressure from the sitting or supine position.

Most people, then, have less of a decrease in blood pressure than that between supine and standing.

Like many more people than I had assumed before reading this thread, I prefer to work lying down: because I get less sleepy that way. I have done so for >10 years, whenever I have the option.

You may be dealing with significant sleep deprivation, if you lying down affects you this way.

Not sleep deprived but use bed for sleep only. You working while lying down is more unusual, most people are the opposite but whatever floats your boat. For the average person it’s probably a bad idea and might weaken your body if you lie down too much. I am actually at a stand up desk a portion of the workday and I feel it has come with some positive effects, makes me more alert in the morning, my back feels better, etc