James, P.A., Oparil, S., Carter, B.L., Cushman, W.C., Dennison-Himmelfarb, C., Handler, J., & Ortiz, E. (2013, December 18). 2014 evidence-based guideline for the management of high blood pressure in adults: Report from the panel members appointed to the eighth joint national committee. Journal of the American Medical Association. Retrieved from http://jamanetwork.com/journals/jama/fullarticle/1791497
Up to 40% of patients taking clonidine (Catapres) will experience dry mouth and about a third will have drowsiness, headache, and sleepiness. Other common side effects include constipation, dizziness, and local skin reactions with use of the Catapres-TTS skin patch. Reserpine use is linked with possible side effects including nightmares, stuffy nose, depression, and an inability to fall asleep. Diarrhea and heartburn are also possible. Guanadrel and guanethidine can cause diarrhea and other gastrointestinal issues – as well as dizziness and drowsiness.
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.
If your blood pressure is always on the low side and you do not have any of the above symptoms, there is usually no cause for concern. Similarly, if you have a single at-home blood pressure reading that is abnormally low without any symptoms, you probably do not need to see your doctor. It is normal for your blood pressure to rise and fall over time, and your body is usually able to get your blood pressure back to normal.
Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.
You can have high blood pressure, or hypertension, and still feel just fine. That's because high blood pressure often does not cause signs of illness that you can see or feel. But, high blood pressure, sometimes called "the silent killer," is very common in older people and a major health problem. If high blood pressure isn't controlled with lifestyle changes and medicine, it can lead to stroke, heart disease, eye problems, kidney failure, and other health problems. High blood pressure can also cause shortness of breath during light physical activity or exercise.
Though essential hypertension remains somewhat mysterious, it has been linked to certain risk factors. High blood pressure tends to run in families and is more likely to affect men than women. Age and race also play a role. In the United States, blacks are twice as likely as whites to have high blood pressure, although the gap begins to narrow around age 44. After age 65, black women have the highest incidence of high blood pressure.
Last year, new guidelines from the American Heart Association, the American College of Cardiology, and nine other health organizations lowered the numbers for the diagnosis of hypertension (high blood pressure) to 130/80 millimeters of mercury (mm Hg) and higher for all adults. The previous guidelines set the threshold at 140/90 mm Hg for people younger than age 65 and 150/80 mm Hg for those ages 65 and older.

In people aged 18 years or older hypertension is defined as either a systolic or a diastolic blood pressure measurement consistently higher than an accepted normal value (this is above 129 or 139 mmHg systolic, 89 mmHg diastolic depending on the guideline).[5][7] Other thresholds are used (135 mmHg systolic or 85 mmHg diastolic) if measurements are derived from 24-hour ambulatory or home monitoring.[79] Recent international hypertension guidelines have also created categories below the hypertensive range to indicate a continuum of risk with higher blood pressures in the normal range. The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure (JNC7) published in 2003[27] uses the term prehypertension for blood pressure in the range 120–139 mmHg systolic or 80–89 mmHg diastolic, while European Society of Hypertension Guidelines (2007)[86] and British Hypertension Society (BHS) IV (2004)[87] use optimal, normal and high normal categories to subdivide pressures below 140 mmHg systolic and 90 mmHg diastolic. Hypertension is also sub-classified: JNC7 distinguishes hypertension stage I, hypertension stage II, and isolated systolic hypertension. Isolated systolic hypertension refers to elevated systolic pressure with normal diastolic pressure and is common in the elderly.[27] The ESH-ESC Guidelines (2007)[86] and BHS IV (2004)[87] additionally define a third stage (stage III hypertension) for people with systolic blood pressure exceeding 179 mmHg or a diastolic pressure over 109 mmHg. Hypertension is classified as "resistant" if medications do not reduce blood pressure to normal levels.[27] In November 2017, the American Heart Association and American College of Cardiology published a joint guideline which updates the recommendations of the JNC7 report.[88]
Do not attempt to lower extremely elevated blood pressure in yourself or someone else. While the goal is to reduce blood pressure before additional complications develop, blood pressure should be reduced over the course of hours to days, depending on severity. It is important not to lower blood pressure too quickly, because rapid blood pressure reductions can cut off the supply of blood to the brain, leading to brain damage or death.
High blood pressure can cause problems for a mother and her baby. High blood pressure can harm a mother’s kidneys and other organs and can cause early birth and low birth weight. If you are thinking about having a baby and have high blood pressure, talk with your doctors so you can take steps to lower or control your high blood pressure before and during the pregnancy.
Blood pressure is written as two numbers, such as 112/78 mm Hg. The top, systolic, number is the pressure when the heart beats. The bottom, diastolic, number is the pressure when the heart rests between beats. Normal blood pressure is below 120/80 mm Hg. If you’re an adult and your systolic pressure is 120 to 139, or your diastolic pressure is 80 to 89 (or both), you have pre-hypertension. High blood pressure is a pressure of 140 systolic or higher and/or 90 diastolic or higher that stays high over time.
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]
^ Jump up to: a b c Giuseppe, Mancia; Fagard, R; Narkiewicz, K; Redon, J; Zanchetti, A; Bohm, M; Christiaens, T; Cifkova, R; De Backer, G; Dominiczak, A; Galderisi, M; Grobbee, DE; Jaarsma, T; Kirchhof, P; Kjeldsen, SE; Laurent, S; Manolis, AJ; Nilsson, PM; Ruilope, LM; Schmieder, RE; Sirnes, PA; Sleight, P; Viigimaa, M; Waeber, B; Zannad, F; Redon, J; Dominiczak, A; Narkiewicz, K; Nilsson, PM; et al. (July 2013). "2013 ESH/ESC Guidelines for the management of arterial hypertension: The Task Force for the management of arterial hypertension of the European Society of Hypertension (ESH) and of the European Society of Cardiology (ESC)". European Heart Journal. 34 (28): 2159–219. doi:10.1093/eurheartj/eht151. PMID 23771844.
Hypertension Stage 1 is when blood pressure consistently ranges from 130-139 systolic or 80-89 mm Hg diastolic. At this stage of high blood pressure, doctors are likely to prescribe lifestyle changes and may consider adding blood pressure medication based on your risk of atherosclerotic cardiovascular disease (ASCVD), such as heart attack or stroke.
The NHLBI is part of the U.S. Department of Health and Human Services’ National Institutes of Health (NIH)—the Nation’s biomedical research agency that makes important scientific discovery to improve health and save lives. We are committed to advancing science and translating discoveries into clinical practice to promote the prevention and treatment of heart, lung, blood, and sleep disorders, including high blood pressure. Learn about the current and future NHLBI efforts to improve health through research and scientific discovery.

When blood pressure is measured, there are two numbers for each reading: for example, "120 over 80" is written as 120/80. This is because each heartbeat sends a pressure wave through the bloodstream. The higher number (systolic blood pressure) is the peak of the wave, when your heart contracts (the loud "thump" when you listen to your heartbeat). The lower number (diastolic blood pressure) is the lower "dip" or trough of the wave, when your heart relaxes.
For older people, often the first number (systolic) is 130 or higher, but the second number (diastolic) is less than 80. This problem is called isolated systolic hypertension, which is due to age-related stiffening of the major arteries. It is the most common form of high blood pressure in older people and can lead to serious health problems (stroke, heart disease, eye problems, and kidney failure) in addition to shortness of breath during light physical activity, lightheadedness upon standing too fast, and falls. Isolated systolic hypertension is treated in the same way as regular high blood pressure (130 or higher for the first number, or 80 or higher for the second number) but may require more than one type of blood pressure medication. If your doctor determines that your systolic pressure is above a normal level for your age, ask how you can lower it.
Dizziness : While dizziness can be a side effect of some blood pressure medications, it is not caused by high blood pressure. However, dizziness should not be ignored, especially if the onset is sudden. Sudden dizziness, loss of balance or coordination and trouble walking are all warning signs of a stroke. High blood pressure is a leading risk factor for stroke.
^ Expert Panel on Integrated Guidelines for Cardiovascular Health and Risk Reduction in Children and Adolescents, National Heart, Lung, and Blood Institute (Dec 2011). "Expert panel on integrated guidelines for cardiovascular health and risk reduction in children and adolescents: summary report". Pediatrics. 128 Suppl 5: S213–56. doi:10.1542/peds.2009-2107C. PMC 4536582. PMID 22084329.
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for general informational purposes only and does not address individual circumstances. It is not a substitute for professional medical advice, diagnosis or treatment and should not be relied on to make decisions about your health. Never ignore professional medical advice in seeking treatment because of something you have read on the WebMD Site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
What is a normal blood pressure? Blood pressure is essential to life because it forces the blood around the body, delivering all the nutrients it needs. Here, we explain how to take your blood pressure, what the readings mean, and what counts as low, high, and normal. The article also offers some tips on how to maintain healthy blood pressure. Read now
×