(If this belongs in a different sub-forum, I apologize)
So, Cecil was kind enough to answer my inquiry about hypertension here. In a nutshell, it’s the salt, not the quantity of blood, that seems to be the problem. Gotcha.
Cecil also contends, in a related article, that taking a schvitz is good for you (or least claims that it’s possible that it’s good for you).
Suppose I had high blood pressure (I don’t). Could I sweat out my excess salt? I know of cyclist friends who complain about white salty residue across their backs from long workouts. If you sit in a sauna, grab some water, and repeat, will you lose a significant amount of salt? Is this a practical way of lowering your salt, in lieu of significant dietary changes?
Yes, you can lose a lot of salt in a sauna. Whether it’s a ‘practical’ method of doing so (and thence to lower your blood pressure) would seem to depend on some ‘real world’ considerations. Not only is there a significant time commitment, there’s also the logistical difficulty in finding a sauna that’s close to your home or work, and is open at a time that’s convenient for you.
One thing to keep in mind is that the rapid and substantial salt loss that occurs from having a sauna may induce changes to your hormones that will tend to raise your blood pressure and stimulate your body to hold on to more salt. If this occurs, I doubt it would be dangerous, but it might tend to offset any benefit from taking a schvitz in the first place. (for those interested, I am thinking of a potential activation of the renin angiotensin system as well as a reflex increase in catecholamine levels)