An exception to this is those with very high blood pressure readings especially when there is poor organ function.[79] Initial assessment of the hypertensive people should include a complete history and physical examination. With the availability of 24-hour ambulatory blood pressure monitors and home blood pressure machines, the importance of not wrongly diagnosing those who have white coat hypertension has led to a change in protocols. In the United Kingdom, current best practice is to follow up a single raised clinic reading with ambulatory measurement, or less ideally with home blood pressure monitoring over the course of 7 days.[79] The United States Preventive Services Task Force also recommends getting measurements outside of the healthcare environment.[80] Pseudohypertension in the elderly or noncompressibility artery syndrome may also require consideration. This condition is believed to be due to calcification of the arteries resulting in abnormally high blood pressure readings with a blood pressure cuff while intra arterial measurements of blood pressure are normal.[81] Orthostatic hypertension is when blood pressure increases upon standing.[82]
These guidelines help guide healthcare practices, and can be related to patient reimbursement and healthcare coverage. The tenth revision of the International Statistical Classification of Diseases and Related Health Problems, or ICD-10, is the set of codes used to designate specific health conditions and allow for reimbursement through health insurance programs.
In Europe hypertension occurs in about 30-45% of people as of 2013.[12] In 1995 it was estimated that 43 million people (24% of the population) in the United States had hypertension or were taking antihypertensive medication.[141] By 2004 this had increased to 29%[142][143] and further to 32% (76 million US adults) by 2017.[7] In 2017, with the change in definitions for hypertension, 46% of people in the United States are affected.[7] African-American adults in the United States have among the highest rates of hypertension in the world at 44%.[144] It is also more common in Filipino Americans and less common in US whites and Mexican Americans.[6][145] Differences in hypertension rates are multifactorial and under study.[146]
Some high blood pressure medications initially cause drowsiness, dizziness, and lightheadedness. Some even cause fainting on the first dose. The body usually adjusts to the effects of these medications and the side effects disappear. Consuming alcohol during the early phase of antihypertensive treatment could be risky because alcohol can also cause dizziness, drowsiness, and lightheadedness.
The guidelines also say that a patient's blood pressure levels should be based on an average of two to three readings on at least two different occasions. It's also reasonable for doctors to screen for "white-coat hypertension," which occurs when blood pressure is elevated in a medical setting but not in everyday life, the authors said. This can be done by having patients measure their blood pressure at home. 
Stress reduction techniques such as biofeedback or transcendental meditation may be considered as an add-on to other treatments to reduce hypertension, but do not have evidence for preventing cardiovascular disease on their own.[125][126][127] Self-monitoring and appointment reminders might support the use of other strategies to improve blood pressure control, but need further evaluation.[128]