As for when to check your blood pressure, the most important thing is to do it consistently the same time of the day (ask the doctor which time he prefers and also what time in relation to taking your medication). The following article has a lot of good information for someone just starting to monitor their blood pressure: https://www.drugs.com/cg/how-to-take-a-blood-pressure.html
Anyone can develop hypotension, but certain groups of people are more likely to experience it, and there are different types. For instance, orthostatic (positional) hypotension, which occurs when you stand up after sitting or lying down, is more common in older adults. Typically, “your body has certain compensatory mechanisms to prevent your blood pressure from falling when you stand up,” explains Willie Lawrence, MD, an interventional cardiologist at Research Medical Center in Kansas City, Missouri, and a spokesperson for the American Heart Association. But, he adds, “orthostatic hypotension is a problem for some people because these reflexes that should occur, don’t occur.”
‘White coat syndrome’ refers to elevated blood pressure due to nervousness or anxiety when clients have their blood pressure taken by a healthcare provider. This occurs in approximately 20% of clients. Key message: have the client take their blood pressure at home with an automatic home blood pressure cuff and compare the findings. Alternatively, you can ask the client to sit quietly and leave the room while an automatic cuff takes a client’s blood pressure. The automatic cuff can be programmed to take three measurements and the blood pressure documented is an average of the three readings.
Sprinkling ground flaxseed over your meals can make a big impact on your blood pressure readings. In a 2013 study published in the journal Hypertension, participants with high blood pressure and peripheral artery disease ate 30 grams (about an ounce) of milled flaxseed daily. After six months, their systolic blood pressure (the top number) went down by 15 mm Hg, on average, and their diastolic blood pressure (the bottom number) dropped by 7 mm Hg.
Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. J Am Coll Cardiol. 2018;71(19):e127-e248. PMID: 29146535 www.ncbi.nlm.nih.gov/pubmed/29146535.