I can't say for certain what's causing your midday-evening BP rise.
If I was to guess, I'd say either; electrolyte imbalance, increased sympathetic tone (a rise in cortisol, norepinephrine) or a reduction of the nitric oxide system.
How's your sleep pattern? And I'll harp on my favorite to blame condition, sleep apnea. Any possibility of sleep apnea?
reading some of the links that you have-I have allergies and can't breath for shit, so that probably explains some of it...didn't know that was a factor till I read the post
thanks Stewie