Have you tried taking readings from both arms to see if they closely match?
You have taken blood pressure at least 2 hours after eating each time? or not immediately after medication is taken?
sir over the last three months ive had episodes of high diastolic pressure ( upto110) followed by very low overall bp as low as 89 over57 all within minutes .palpitations and headaches usally accompany these episodes.. my normal bp averages 127/63 would you be able to offer some suggestions as to possible causes of this...
Just another line of thought, my Mother in law had very similar problems where she would feel a sudden head rush and actually fainted several times. It turned out that her Carotid arteries were substantially blocked. When her blood pressure dropped to normal levels, she had insufficient oxygen reaching the brain, causing her to black out.
I believe a CT scan or even an echocardiogram doppler can detect if this is a problem.
Has his kidney function been tested? If one or both are not functioning at 100% it causes the BP to rise, and may be why he doesn't feel well. A bulging disc can press on a nerve causing many problems. This needs to be evaluated by an Orthopaedist.