Unfortunately, a problem doesn’t always announce itself with a fanfare of trumpets. Even the highest blood pressure can be entirely asymptomatic. Similarly, low blood pressure also known as hypotension can occur in your patient despite no symptoms seemingly being present. This is particularly true if the patient is lying still in an unmonitored bed.
Peter, I’ve been using a blood pressure meter for nearly 30 years, so my response is based on my personal experience and information I’ve acquired over the years. First, I suggest that you take your meter to the doctor and have them check several readings of your meter against theirs. For example, If your meter consistently shows it’s 10 points lower than the doctor’s, just delete the 10 points from your meter reading (have them check both numbers so you can adjust both as necessary). Also, it’s common that many doctor’s offices take your blood pressure incorrectly (you should actually sit still for 5 minutes, with your feet on the floor and the cuff at the same level as your heart) . Some of us have”white coat” hypertension, so you may always be elevated at the doctor’s office. If you are a large man, you (and your doctor’s office) may need to use a larger cuff as the wrong size of cuff can affect your reading. Also, I spoke with customer service at one of the companies that makes many of the home & professional meters, and she told me that the automated machines are not very accurate if you have kidney disease or heart failure (I have both). Ask the doctor’s staff to always use the manual system and it will be more accurate than those noisy automatic ones.
Changes in blood vessel structure. Blood vessels have layers of the proteins elastin and collagen. Elastin is what makes blood vessels flexible. Collagen, which is stiffer, gives vessels structure. With age, elastin breaks down. Even the elastin that remains becomes less elastic. Meanwhile, collagen deposits in the vessels increase. As a result, blood vessels grow thicker and bend less easily over time. These changes may lead to higher systolic blood pressure.
^ Martin-Cabezas, Rodrigo; Seelam, Narendra; Petit, Catherine; Agossa, Kévimy; Gaertner, Sébastien; Tenenbaum, Henri; Davideau, Jean-Luc; Huck, Olivier (October 2016). "Association between periodontitis and arterial hypertension: A systematic review and meta-analysis". American Heart Journal. 180: 98–112. doi:10.1016/j.ahj.2016.07.018. ISSN 1097-6744. PMID 27659888.
This study will assess whether minocycline, an antibiotic with anti-inflammatory effects, can improve blood pressure control in patients who do not respond to medicines in combination with lifestyle changes, such as physical activity, weight loss, and healthy eating patterns. To participate you must be at least 18 years old and have high blood pressure that does not respond to treatment with three different high blood pressure medicines even when used at the maximum doses. Please note that this study is in Gainesville, Florida.
Recurrent headaches: Headaches are fairly common among people with or without hypertension. Some people with hypertension notice changes or worsening of headaches when medications are skipped or when the blood pressure becomes higher than usual. Headaches associated with hypertension can be mild, moderate, or severe and can be of a throbbing nature. 
The measurements must have been obtained from at least two careful readings on at least two different occasions. What does careful mean? The guidelines provide a six-step tutorial on how, exactly, to correctly measure a blood pressure, which, admittedly, is sorely needed. My patients often have their first blood pressure taken immediately after they have rushed in through downtown traffic, as they’re sipping a large caffeinated beverage. While we always knew this could result in a falsely elevated measurement, it is now officially poor clinical technique resulting in an invalid reading.
Some forms of postural hypotension may require a test called a "tilt table" test. This test evaluates the body's reaction to changes in position. The person lies on a table, is safely strapped in, and the table is raised to an upright position for up to an hour. Blood pressure, heart rate, and symptoms are recorded. Often, medications are given to help guide treatment.
Understanding the normal BP range with age can help the doctor and you to estimate your cardiovascular health. Blood pressure levels can fluctuate significantly from one reading to the next and it is important to remember that just one abnormally high reading does not signify that you have high blood pressure. Doctors usually use an average of multiple blood pressure readings taken over a period of several days to arrive at a diagnosis of high blood pressure.

Drinking too much alcohol is a risk factor for high blood pressure. The American Heart Association guidelines recommend the consumption of no more than two alcoholic drinks per day for men and no more than one drink a day for women. One drink is defined as one 12-ounce beer, 4 ounces of wine, 1.5 ounces of 80-proof spirits, or 1 ounce of 100-proof spirits. Adults who consume more than three drinks in one sitting temporarily increase their blood pressure. However, binge drinking can lead to long-term increased blood pressure.

^ Mente, Andrew; O'Donnell, Martin; Rangarajan, Sumathy; Dagenais, Gilles; Lear, Scott; McQueen, Matthew; Diaz, Rafael; Avezum, Alvaro; Lopez-Jaramillo, Patricio; Lanas, Fernando; Li, Wei; Lu, Yin; Yi, Sun; Rensheng, Lei; Iqbal, Romaina; Mony, Prem; Yusuf, Rita; Yusoff, Khalid; Szuba, Andrzej; Oguz, Aytekin; Rosengren, Annika; Bahonar, Ahmad; Yusufali, Afzalhussein; Schutte, Aletta Elisabeth; Chifamba, Jephat; Mann, Johannes F E; Anand, Sonia S; Teo, Koon; Yusuf, S (July 2016). "Associations of urinary sodium excretion with cardiovascular events in individuals with and without hypertension: a pooled analysis of data from four studies". The Lancet. 388 (10043): 465–75. doi:10.1016/S0140-6736(16)30467-6. PMID 27216139.
Hypertension occurs in around 0.2 to 3% of newborns; however, blood pressure is not measured routinely in healthy newborns.[33] Hypertension is more common in high risk newborns. A variety of factors, such as gestational age, postconceptional age and birth weight needs to be taken into account when deciding if a blood pressure is normal in a newborn.[33]
Facial flushing: Facial flushing occurs when blood vessels in the face dilate. It can occur unpredictably or in response to certain triggers such as sun exposure, cold weather, spicy foods, wind, hot drinks and skin-care products. Facial flushing can also occur with emotional stress, exposure to heat or hot water, alcohol consumption and exercise — all of which can raise blood pressure temporarily. While facial flushing may occur while your blood pressure is higher than usual, high blood pressure is not the cause of facial flushing.