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.
Low blood pressure (hypotension) is pressure so low it causes symptoms or signs due to the low flow of blood through the arteries and veins. When the flow of blood is too low to deliver enough oxygen and nutrients to vital organs such as the brain, heart, and kidney, the organs do not function normally and may be temporarily or permanently damaged.
About This Image: Person receiving a blood pressure test. Medical research shows that as we age blood pressure rises slightly to accommodate an increased demand of oxygen and nutrients. It is completely natural for the first number (systolic) to be 100 plus our age. A recent study by a group of UCLA researchers came very close to corroborating Dr. Piette's guide for blood pressure of 100 plus your age for men, subtracting 10 for women, and this is after this rule had been in use for five or more decades. Are we now being taught that Dr. Piette's guide for blood pressure is wrong merely for drug company profit?
^ 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.
^ Jump up to: a b Go, AS; Bauman, M; King, SM; Fonarow, GC; Lawrence, W; Williams, KA; Sanchez, E (15 November 2013). "An Effective Approach to High Blood Pressure Control: A Science Advisory From the American Heart Association, the American College of Cardiology, and the Centers for Disease Control and Prevention". Hypertension. 63 (4): 878–85. doi:10.1161/HYP.0000000000000003. PMID 24243703. Archived from the original on 20 November 2013. Retrieved 20 November 2013.
Keeping track of your blood pressure is important. Your doctor can help you learn how to check your blood pressure at home. Each time you check your own blood pressure, record your numbers and the date. Send or take the log of your blood pressure readings with you for appointments with your doctor. Return to Screening for reminders on how to prepare for blood pressure testing. 

2. Take the right nutrients. Talk with your chiropractor or other healthcare professional about the wide range of well-studied nutrients that, along with dietary and lifestyle modifications, can help normalize your blood pressure. One meta-analysis found magnesium supplements could lower blood pressure. Likewise, researchers find a small but significant decline in blood pressure for people with hypertension who use fish oil. (You can get all of fish oil’s benefits combined with anti-inflammatory flax oil and GLA in our Optimal Omega.) 
Patient-activated event recorder: If the episodes of bradycardia or tachycardia are infrequent, a 24-hour Holter recording may not capture these sporadic episodes. In this situation, a patient can wear a patient-activated event recorder for up to 4 weeks. The patient presses a button to start the recording when he or she senses the onset of an abnormal heart rhythm or symptoms possibly caused by low blood pressure. The doctor then analyzes the recordings later to identify the abnormal episodes.

Primary (or essential) hypertension is when the cause is unknown. The majority of hypertension cases are primary. When there is an underlying problem such as kidney disease or hormonal disorders that can cause hypertension, it is called secondary hypertension. When it is possible to correct the underlying cause, high blood pressure usually improves and may even return to normal. 

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. 

Although the guidelines do not change the traditional definition of high blood pressure, they do call for more aggressive treatment of the condition through the use of a combination of blood-pressure lowering medications. In fact, they say that most people with high blood pressure will require two or more drugs to achieve a blood pressure goal of less than 140/90. The blood pressure goal in people with diabetes or kidney disease should be less than 130/80.
The best evidence indicates that high blood pressure does not cause headaches or nosebleeds, except in the case of hypertensive crisis, a medical emergency when blood pressure is 180/120 mm Hg or higher. If your blood pressure is unusually high AND you have headache or nosebleed and are feeling unwell, wait five minutes and retest. If your reading remains at 180/120 mm Hg or higher, call 9-1-1.  
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.

^ 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.

If your systolic and diastolic blood pressure are in two different categories, doctors consider the number that is in the higher category. For example, if your blood pressure is 135/91, your systolic blood pressure is in the prehypertensive range and your diastolic blood pressure is in the range of Stage 1 hypertension. Your measurement or 135/91 would place you in the category of Stage 1 hypertension.
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
In the 19th and 20th centuries, before effective pharmacological treatment for hypertension became possible, three treatment modalities were used, all with numerous side-effects: strict sodium restriction (for example the rice diet[152]), sympathectomy (surgical ablation of parts of the sympathetic nervous system), and pyrogen therapy (injection of substances that caused a fever, indirectly reducing blood pressure).[152][158]

SOURCES: The Journal of the American Medical Association, May 21, 2003. Aram Chobanian, MD, dean, Boston University School of Medicine and chair of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Claude Lenfant, MD, director of the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health. Edward Roccella, PhD, MPH, coordinator of the National High Blood Pressure Education Program at NHLBI. John Laragh, MD, Cardiovascular Hypertension Center at New York Hospital/Cornell University Medical Center and editor-in-chief of the American Journal of Hypertension. WebMD Medical News: "Diuretics Best for High Blood Pressure."
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.
Blood pressure is measured with a blood pressure cuff (sphygmomanometer). This may be done using a stethoscope and a cuff and gauge or by an automatic machine. It is a routine part of the physical examination and one of the vital signs often recorded for a patient visit. Other vital signs include pulse rate, respiratory rate (breathing rate), temperature, and weight.
Preeclampsia is elevated blood pressure and the leakage of protein into the urine by the kidneys. Preeclampsia can be dangerous to both mother and baby. High blood pressure during pregnancy may lead to decreased blood flow to the placenta, placental abruption, premature delivery, or future cardiovascular disease. After the baby is born, high blood pressure during pregnancy usually returns to normal levels.
If you have high blood pressure, it is important to get routine medical care and to follow your prescribed treatment plan, which will include heart-healthy lifestyle changes and possibly medicines. Heart-healthy lifestyle changes can prevent high blood pressure, reduce elevated blood pressure, help control existing high blood pressure, and prevent complications, such as heart attack, heart failure, stroke, vascular dementia, or chronic kidney disease.
Hypertension defined as elevated blood pressure over several visits affects 1% to 5% of children and adolescents and is associated with long term risks of ill-health.[89] Blood pressure rises with age in childhood and, in children, hypertension is defined as an average systolic or diastolic blood pressure on three or more occasions equal or higher than the 95th percentile appropriate for the sex, age and height of the child. High blood pressure must be confirmed on repeated visits however before characterizing a child as having hypertension.[89] Prehypertension in children has been defined as average systolic or diastolic blood pressure that is greater than or equal to the 90th percentile, but less than the 95th percentile.[89] In adolescents, it has been proposed that hypertension and pre-hypertension are diagnosed and classified using the same criteria as in adults.[89]
High blood pressure, or hypertension, most commonly occurs without any symptoms and has for this reason been referred to as the "silent killer." Uncomplicated hypertension can persist for years, even decades, without causing symptoms. However, when complications of the condition begin to develop due to damage to the vascular system, symptoms can occur. Symptoms of complicated hypertension (high blood pressure) can include dizziness, shortness of breath, headache, and blurred vision. Other possible symptoms are nosebleeds, blood in the urine, fatigue, chest pain, and a pounding sensation in the neck, chest, or ears.
Hypertensive Crisis This is an occurrence of high blood pressure that requires medical attention. If you have a blood pressure reading of 180/120 mm Hg, wait five minutes and test again. If it is consistently this high, contact your doctor immediately. If blood pressure is higher than 180/120 mm Hg and you are experiencing chest pain, shortness of breath, back pain, numbness and weakness, change in vision, and difficulty speaking, you may have organ damage and should call 911. (4)

One especially important cause of low blood pressure is orthostatic hypotension, which is sometimes referred to as postural hypotension. This happens when blood pressure drops rapidly during changes in body position—usually when changing from sitting to standing—inducing classic signs that the blood pressure is too low, like dizziness, blurry vision, and fainting.
Medications used to lower blood pressure include diuretics (e.g., hydrochlorothiazide*), beta-blockers (e.g., atenolol, metoprolol), ACE inhibitors (e.g., ramipril, enalapril, lisinopril), calcium channel blockers (e.g., nifedipine, amlodipine), angiotensin II receptor blockers (e.g., losartan, valsartan), and direct renin inhibitors (e.g., aliskiren).
As mentioned earlier, blood pressure increases with age, beginning from infancy to older adulthood. Since most healthy babies and children are typically not at risk for blood pressure problems, most doctors do not check their blood pressure routinely. But, the normal BP range for all adults, regardless of their age, is considered to be lesser than 120/80.
How the heart pumps blood into the arteries with enough force to push blood to the far reaches of each organ from the top of the head to the bottom of the feet. Blood pressure can be defined as the pressure of blood on the walls of the arteries as it circulates through the body. Blood pressure is highest as its leaves the heart through the aorta and gradually decreases as it enters smaller and smaller blood vessels (arteries, arterioles, and capillaries). Blood returns in the veins leading to the heart, aided by gravity and muscle contraction.
During relaxation of the heart (diastole), the left ventricle of the heart fills with blood returning from the lungs. The left ventricle then contracts and pumps blood into the arteries (systole). The blood pressure in the arteries during contraction of the ventricle (systolic pressure) is higher because blood is being actively ejected into the arteries. It is lower during relaxation of the ventricle (diastolic pressure) when no blood is being ejected into the arteries. The pulse we feel when we place our fingers over an artery is caused by the contraction of the left ventricle and the ejection of blood.
Calcium channel blockers are drugs that reduce the movement of calcium into cells of the heart and vessels. This reduces the strength of heart contractions and relaxes the arteries, allowing them to remain more open, lowering blood pressure. Side effects of calcium channel blockers can include heart palpitations, dizziness, swollen ankles, and constipation. Calcium channel blockers can be taken alone or with other blood pressure medications. They should be taken with food or milk. Because of potential interactions, those taking calcium channel blockers should avoid alcohol and grapefruit juice.
Recent updates to guidelines from the American Heart Association and the American College of Cardiology changed the definition of high blood pressure or hypertension for most people. High blood pressure is now generally defined as 130 or higher for the first number, or 80 or higher for the second number (previously it was 140/90). However, there are important considerations for older adults in deciding whether to start treatment for high blood pressure, including other health conditions and overall fitness. If your blood pressure is above 130/80, your doctor will evaluate your health to determine what treatment is needed to balance risks and benefits in your particular situation.
Low blood pressure is not always a sign of a problem. But if you have symptoms of low blood pressure, your doctor can diagnose the condition and uncover the cause. Symptoms of dizziness and lightheadedness when you stand up from sitting or lying down -- with a decrease in your blood pressure -- may indicate a condition called postural hypotension. A wide range of underlying conditions may also cause your symptoms. It's important to identify the cause of low blood pressure so appropriate treatment can be given.

According to guidelines from the American Heart Association (AHA) and the American College of Cardiology (ACC), a reading below 120/80 mm Hg is classified as normal blood pressure. Those with a blood pressure reading anywhere from 120/80 up to 129/80 are classified within a category called elevated blood pressure. Hypertension is defined as a reading of 130/80 or higher.
Hypertension is actually of two types, one is called Primary Hypertension or Essential Hypertension, and this type of hypertension develops gradually over the years as a person ages, and it has no known causes. The other type of hypertension is called Secondary Hypertension, and this type is caused by different diseases, and a person’s lifestyle factors, like diet, sedentary lifestyle, alcohol intake etc.
Postural hypotension is considered to be a failure of a person's cardiovascular system or nervous system to react appropriately to sudden changes. Usually, when a person stands up, some of their blood pools in their lower extremities. If this remains uncorrected, it would cause the person's blood pressure to fall or decrease. A person's body usually compensates by sending messages to their heart to beat faster and to their blood vessels to constrict, offsetting the drop in blood pressure. If this does not happen, or does not happen quickly enough, postural hypotension is the result.

Hypertension with certain specific additional signs and symptoms may suggest secondary hypertension, i.e. hypertension due to an identifiable cause. For example, Cushing's syndrome frequently causes truncal obesity, glucose intolerance, moon face, a hump of fat behind the neck/shoulder (referred to as a buffalo hump), and purple abdominal stretch marks.[23] Hyperthyroidism frequently causes weight loss with increased appetite, fast heart rate, bulging eyes, and tremor. Renal artery stenosis (RAS) may be associated with a localized abdominal bruit to the left or right of the midline (unilateral RAS), or in both locations (bilateral RAS). Coarctation of the aorta frequently causes a decreased blood pressure in the lower extremities relative to the arms, or delayed or absent femoral arterial pulses. Pheochromocytoma may cause abrupt ("paroxysmal") episodes of hypertension accompanied by headache, palpitations, pale appearance, and excessive sweating.[23]
Hypertension results from a complex interaction of genes and environmental factors. Numerous common genetic variants with small effects on blood pressure have been identified[34] as well as some rare genetic variants with large effects on blood pressure.[35] Also, genome-wide association studies (GWAS) have identified 35 genetic loci related to blood pressure; 12 of these genetic loci influencing blood pressure were newly found.[36] Sentinel SNP for each new genetic locus identified has shown an association with DNA methylation at multiple nearby CpG sites. These sentinel SNP are located within genes related to vascular smooth muscle and renal function. DNA methylation might affect in some way linking common genetic variation to multiple phenotypes even though mechanisms underlying these associations are not understood. Single variant test performed in this study for the 35 sentinel SNP (known and new) showed that genetic variants singly or in aggregate contribute to risk of clinical phenotypes related to high blood pressure.[36]

Quitting smoking. Visit Smoking and Your Heart and the National Heart, Lung, and Blood Institute’s Your Guide to a Healthy Heart [PDF – 2MB]. Although these resources focus on heart health, they include basic information about how to quit smoking. For free help and support to quit smoking, you can call the National Cancer Institute’s Smoking Quitline at 1-877-44U-QUIT (1-877-448-7848).
Echocardiogram is an ultrasound examination of the heart It is used to evaluate the anatomy and the function of the heart. A cardiologist is required to interpret this test and can evaluate the heart muscle and determine how thick it is, whether it moves appropriately, and how efficiently it can push blood out to the rest of the body. The echocardiogram can also assess heart valves, looking for narrowing (stenosis) and leaking (insufficiency or regurgitation). A chest X-ray may be used as a screening test to look for heart size, the shape of the aorta, and to assess the lungs.
Finding out what genetic patterns contribute to high blood pressure risk. NHLBI-funded researchers identified dozens of new genetic variations that affect blood pressure. Scientists discovered the new genetic regions—and confirmed the role of many previously known ones by looking specifically at cigarette smoking behavior, one of many lifestyle factors that impact blood pressure. The analysis of the large samples was possible through the work of researchers in the Gene-Lifestyle Interactions Working Group of the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Consortium.
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
^ 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.

^ Jump up to: a b Brook RD, Appel LJ, Rubenfire M, Ogedegbe G, Bisognano JD, Elliott WJ, Fuchs FD, Hughes JW, Lackland DT, Staffileno BA, Townsend RR, Rajagopalan S, American Heart Association Professional Education Committee of the Council for High Blood Pressure Research, Council on Cardiovascular and Stroke Nursing, Council on Epidemiology and Prevention, and Council on Nutrition, Physical, Activity (Jun 2013). "Beyond medications and diet: alternative approaches to lowering blood pressure: a scientific statement from the American Heart Association". Hypertension. 61 (6): 1360–83. doi:10.1161/HYP.0b013e318293645f. PMID 23608661.
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]
Beta-blockers cause the heart to slow down and so some of their side effects can be traced to that mechanism of action. Dizziness, weakness, fatigue, and fainting are possible. Beta-blockers also affect the respiratory system, so other side effects include shortness of breath, difficulty breathing, and chest pain. Beta-blockers should not be withdrawn suddenly, as that could result in a heart attack or sudden death.
Low blood pressure due to nervous system damage (multiple system atrophy with orthostatic hypotension). Also called Shy-Drager syndrome, this rare disorder causes progressive damage to the autonomic nervous system, which controls involuntary functions such as blood pressure, heart rate, breathing and digestion. It's associated with having very high blood pressure while lying down.
Postural hypotension is considered a failure of the cardiovascular system or nervous system to react appropriately to sudden changes. Normally, when you stand up, some blood pools in your lower extremities. Uncorrected, this would cause your blood pressure to fall. But your body normally compensates by sending messages to your heart to beat faster and to your blood vessels to constrict. This offsets the drop in blood pressure. If this does not happen, or happens too slowly, postural hypotension results and can lead to fainting.
Blood pressure monitors for use at home can be bought at drug stores, department stores, and other places. Again, these monitors may not always give you a correct reading. You should always compare your machine’s reading with a reading from your doctor’s machine to make sure they are the same. Remember that any measurement above normal should prompt a visit to the doctor, who can then talk with you about the best course of action.
This study is exploring whether use of losartan, a medicine commonly used to lower blood pressure, is effective at treating abnormal nighttime blood pressure in children and young adults who have sickle cell disease. To participate in this study, you or your child must be 5 to 25 years old and have high blood pressure and a certain type of sickle cell disease: hemoglobin SS or Sβ0 thalassemia. This study is located in Birmingham, Alabama.
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