The term "underlying health conditions" should be qualified with the word "known", ie "known underlying health conditions".
If somebody is suffering from high blood pressure and are treated for it, doesn't that suggest they now
don't have high blood pressure?
So is the actual risk from untreated high BP, or treated high BP, or is it connected to the underlying reason for the high BP?
Too many suggestions(backed by evidence) of contradictory advice that might be helpful or might be harmful. Difficult to discuss those without the heavy risk of people following the wrong route or going to extremes. Eg In Iran the notion of alcohol fixing it, has led to hundreds of people being killed by methanol or ethanol poisoning.