Causes Of Low Diastolic Blood Pressure
There are three known causes of isolated diastolic hypotension:
- Alpha-blocker medications. These blood pressure medications work by causing your blood vessels to open up . Because they lower diastolic pressure more than systolic pressure, they may cause isolated diastolic hypotension. Common brand names include Minipress and Cardura.
- The aging process. As we age, we lose the elasticity of our arteries. For some older adults, arteries may become too stiff to spring back between heartbeats, causing diastolic blood pressure to be low.
- Too much salt in your diet. Dietary salt can decrease elasticity of your blood vessels. If you take in too much salt, you may increase your risk for low diastolic blood pressure.
There are several common causes of overall hypotension, which would include a low diastolic number.
- Overtreatment of high blood pressure. For some people, especially people over age 60, lowering systolic blood pressure below 120 may cause diastolic pressure to fall below 60.
Low Blood Pressure Symptoms
Low blood pressure 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.
Unlike high blood pressure, low blood pressure is defined primarily by signs and symptoms of low blood flow and not by a specific blood pressure number. Some individuals routinely may have blood pressure numbers of 90/50 with no symptoms and therefore do not have low blood pressure. However, others who normally have higher blood pressures may develop symptoms of low blood pressure if their blood pressure drops to 100/60.
Beware Of Blood Pressure Changes At Night
When systolic blood pressure jumps up by 20 mm/Hg or more during the night, the risk of heart disease and stroke goes up by 18% and the risk of heart failure increases by 25%.
If people consistently had higher blood pressure readings at night, but normal readings during the day, the risk of heart failure more than doubled. The researchers, writing in the journal Circulation, dubbed this a “riser pattern.”
On the other hand, for people with a drop in blood pressure of more than 20%, the study team noted a more than twice the risk of stroke. They called this group “extreme dippers.”
“Nighttime blood pressure is increasingly being recognized as a predictor of cardiovascular risk,” study lead author Dr. Kazuomi Kario said in a journal news release. He’s chair of cardiovascular medicine at the Jichi Medical University in Tochigi, Japan.
Dr. Raymond Townsend, an expert volunteer for the American Heart Association, said blood pressure is typically higher in the morning and lower in the afternoon and evening.
Compared to the overall daytime blood pressure pattern, “blood pressure is generally about 10% to 20% lower during sleep. Sleep time offers a relatively pure look at blood pressure. Most factors that influence blood pressure are minimized during sleep,” he explained.
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If You Notice A Sudden Decline In Blood Pressure
A single lower-than-normal reading is not cause for alarm, unless you are experiencing any other symptoms or problems. If you experience any dizziness, lightheadedness, nausea or other symptoms, its a good idea to consult with your healthcare provider. To help with your diagnosis, keep a record of your symptoms and activities at the time they occurred.
Is low blood pressure related to low heart rate? Find out.
Written by American Heart Association editorial staff and reviewed by science and medicine advisers. See our editorial policies and staff.
Last Reviewed: Oct 31, 2016
Can A Person With High Blood Pressure Also End Up With Bouts Of Low Blood Pressure
Dr. Laffin explains that treatment of hypertension can sometimes result in episodes of low blood pressure. In other words, the medication prescribed may lower blood pressure too much. Additionally, certain blood pressure medications have an increased effect if you’re dehydrated, says Dr. Laffin. For example, ARBs and ACE-inhibitors will have more of a blood pressure lowering effect if you’re dehydrated.
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Low Blood Pressure In Elderly People: The Vital Facts You Should Know
Most people are aware that high blood pressure in seniors can lead to serious medical issues, but low blood pressure in elderly individuals gets far less attention. However, blood pressure that drops too low can have equally serious effects on your health. It’s important to know the facts so that you can take proper care of yourself.
A low blood pressure reading is not necessarily cause for panic. While high blood pressure is harmful even if you don’t know you have it, low blood pressure is generally not a problem unless you start experiencing symptoms like dizziness or blurred vision. If that happens, you need to take action. Symptomatic low blood pressure in the elderly can be very dangerous because it raises the risk of a fall. At its most extreme, it can lead to shock and even death.
This article explains the basic facts about blood pressure, including how it’s measured and what the measurements mean. It also describes common symptoms of low blood pressure and outlines a variety of factors that can cause such a condition. And it provides information about different ways that low blood pressure in older adults can be treated or managed.
How To Prevent Feeling Dizzy After Eating
There is no surefire treatment for postprandial hypotension, but these four lifestyle changes can help you prevent low blood pressure:
Various medications and supplements have been tested against postprandial hypotension. These include caffeine, guar gum , acarbose , midodrine , and others. But none of them has performed well in clinical trials, and side effects of these therapies can sometimes be worse than postprandial hypotension.
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What Is Low Blood Pressure
Hypotension is the medical term for low blood pressure .
A blood pressure reading appears as two numbers. The first and higher of the two is a measure of systolic pressure, or the pressure in the arteries when the heart beats and fills them with blood. The second number measures diastolic pressure, or the pressure in the arteries when the heart rests between beats.
Optimal blood pressure is less than 120/80 . In healthy people, low blood pressure without any symptoms is not usually a concern and does not need to be treated. But low blood pressure can be a sign of an underlying problem — especially in the elderly — where it may cause inadequate blood flow to the heart, brain, and other vital organs.
Chronic low blood pressure with no symptoms is almost never serious. But health problems can occur when blood pressure drops suddenly and the brain is deprived of an adequate blood supply. This can lead to dizziness or lightheadedness. Sudden drops in blood pressure most commonly occur in someone who’s rising from a lying down or sitting position to standing. This kind of low blood pressure is known as postural hypotension or orthostatic hypotension. Another type of low blood pressure can occur when someone stands for a long period of time. This is called neurally mediated hypotension.
Changing The Diameter Of Arterioles And Veins
Muscle tissue within the walls of arterioles allow these blood vessels to widen or narrow . The more constricted arterioles are, the greater their resistance to blood flow and the higher the blood pressure. Constriction of arterioles increases blood pressure because more pressure is needed to force blood through the narrower space. Conversely, dilation of arterioles reduces resistance to blood flow, thus reducing blood pressure. The degree to which arterioles are constricted or dilated is affected by
Nerves that contract smooth muscle in the arterioles, thus reducing their diameter
Hormones that are primarily made by the kidneys
Veins also play a role in the control of blood pressure, although their effect on blood pressure is much less than that of arterioles. Veins dilate and constrict to change how much blood they can hold . When veins constrict, their capacity to hold blood is reduced, allowing more blood to return to the heart from which it is pumped into the arteries. As a result, blood pressure increases. Conversely, when veins dilate, their capacity to hold blood is increased, allowing less blood to return to the heart. As a result, blood pressure decreases.
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Reducing Your Salt Intake
The American Heart Association recommends no more than a teaspoon of salt a day for adults. That may sound alarmingly small, but there are many painless ways to reduce your sodium intake.
Reduce canned and processed foods.;Much of the salt you eat comes from canned or processed foods like soups, convenience meals, and fast food.
Cook more meals at home. Preparing your own meals gives you more control over your sodium intake. Use fresh ingredients whenever possible and cook without salt.
Use spices as alternatives to salt. Try fresh herbs like basil, thyme, or chives, or dried spices such as allspice, bay leaves, or cumin to flavor your meal without sodium.
Substitute reduced sodium versions.;Choose your condiments and packaged foods carefully, looking for foods labeled sodium free, low sodium, or unsalted.
See Heart-Healthy Diet Tips to learn more.
The effects on your blood pressure
- Adopting the DASH diet, eating plenty of fruit and vegetables, and reducing your consumption of unhealthy fats can lower your blood pressure by about 11 mm Hg.
- Cutting back on sodium by about 1,000 mg per day can reduce your blood pressure by 5 to 6 mm Hg.
- Increasing your potassium intake from food to 3,500-5,000 mg can knock 4 to 5 mm Hg off your reading.
- Limiting your alcohol intake to two drinks per day if youre male, or one drink per day if youre female can lower your reading by about 4 mm Hg.
Treatment Of Low Diastolic Blood Pressure
Treating isolated diastolic hypotension is more difficult than treating general hypotension. If youre taking an alpha-blocker, your doctor can change you to a different high blood pressure medication.
If you have isolated low diastolic pressure and youre not on blood pressure medication, the only option may be to see your doctor more frequently for checkups and to watch for symptoms of heart failure. Currently, there isnt any medication available to treat isolated diastolic hypotension.
Treatment of general hypotension depends on the cause.
Overtreatment of high blood pressure can be managed by adjusting or changing medications. The goal is to keep the diastolic blood pressure between 60 and 90 mm Hg. Your doctor may also change other medications that cause hypotension.
Dehydration can be treated with fluid replacement. In some cases, you may need medications that increase blood pressure.
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When To Call Your Doctor
Talk to your doctor if you experience a sudden drop in blood pressure accompanied by lightheadedness or dizziness. Take note of how fast your blood pressure drops rather than how much it drops any time you feel dehydrated, spend too much time in the hot tub or in the sun, or have low blood sugar. Keep a diary and record any symptoms and the corresponding activity at the time.
If you have liver or kidney problems, have had a stroke or are at risk of having a stroke, you should have your blood pressure closely monitored. Low blood pressure can interfere with blood supply to your organs and the brain.
What Is Blood Pressure
As blood pumps through the circulatory system, it pushes against the walls of the arteries and veins. Blood pressure is the force of the blood as it presses against the blood vessel walls. It is measured in systolic pressure and diastolic pressure .
Blood pressure rises and falls throughout the day. Normal blood pressure is considered to be below 120/80 mm Hg. In a blood pressure reading, the top number refers to systolic pressure, and the bottom number refers to the diastolic pressure.
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A Reaction To Medication
An adverse reaction to prescribed or over-the-counter medicine can drop blood pressure unexpectedly. Diuretics and other drugs designed to treat hypertension, some anti-depressants, and medication to help with erectile dysfunction can lower blood pressure to unsafe levels. You can also experience a drop in blood pressure if you combine high blood pressure medications with others.
Improving Health With Current Research
Learn about the following ways the NHLBI continues to translate current research into improved health for people with abnormally low blood pressure. Research on this topic is part of the NHLBIs broader commitment to advancing heart and vascular disease scientific discovery.
- Testing Treatments for Cardiac Arrest and Trauma. The Resuscitation Outcomes Consortium clinical trial network tested treatments to address high morbidity and mortality rates from out-of-hospital cardiac arrest and severe traumatic injury. ROC investigators compared different strategies for supplemental fluids in trauma patients who have low blood pressure. Other ROC studies found a link between low blood pressure readings and the need for emergency procedures.
- Understanding How Low Blood Pressure Affects Diverse Populations. NHLBI-supported researchers are studying low blood pressure in different populations. Investigators in the NHLBIs Atherosclerosis Risk in Communities Study found that people who have low blood pressure when standing up, known as orthostatic hypotension, are at higher risk for stroke. In a follow-up study of NHLBIs Honolulu Heart Program, researchers found older Japanese men who had orthostatic hypotension were nearly twice as likely to die within the next four years as those who did not have orthostatic hypotension. NHLBIs Cardiovascular Health Study found that orthostatic hypotension was common in older adults, increases with age, and is linked to cardiovascular diseases.
What Procedures And Tests Diagnose Low Blood Pressure
In some people, particularly relatively healthy ones, symptoms of weakness, dizziness, and fainting raise the suspicion of low blood pressure. In others, an event often associated with low blood pressure, for example, a heart attack, has occurred to cause the symptoms.
Measuring blood pressure in both the lying and standing positions usually is the first step in diagnosing low blood pressure. In patients with symptomatic low blood pressure, there often is a marked drop in blood pressure upon standing, and patients may even develop orthostatic symptoms. The heart rate often increases. The goal is to identify the cause of the low blood pressure. Sometimes the causes are readily apparent . At other times, the cause may be identified by testing:
Research For Your Health
The NHLBI is part of the U.S. Department of Health and Human Services National Institutes of Health the Nations 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 problems associated with low blood pressure. Learn about current and future NHLBI efforts to improve health through research and scientific discovery.
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When To Worry About Low Blood Pressure
We all know that high blood pressure can be dangerous. But what about low blood pressure
Also called hypotension, low blood pressure is not a problem if youre healthy and show no signs or symptoms of the condition. However, abnormally low blood pressure can cause problems such as dizziness and fainting and can be a sign that other serious conditions, such as heart disease, are present.
How Is Resistant Hypertension Treated
Treatment options for resistant hypertension or pseudo-resistant hypertension depend on your underlying conditions and how well you tolerate various medications. Treatments include:
- Addressing any conditions that may have caused the hypertension.
- Making lifestyle changes
- Adjusting medications to find your optimal type and dosage
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Blood Pressure And The Heart
Theres a reason why your blood pressure is taken every time you visit a doctors office or hospital, regardless of the complaint that brought you there. High blood pressure is rightly known as the silent killer. It often carries no symptoms or warning signs but can drastically increase your risk of having a heart attack or stroke. The higher the number, the harder your heart is having to work to pump blood around your body and the more likely it is that damage is being done to the heart muscle. Since all parts of your body rely on circulation, though, its not just your heart that high blood pressure can impact. If blood doesnt flow easily, it can harm your arteries as well as vital organs such as the kidneys, eyes, and brain.
High blood pressure has been shown to damage the tiny blood vessels in the parts of your brain responsible for cognition and memory, greatly increasing your risk of developing Alzheimers disease or another dementia. Being diagnosed with cardiovascular disease can also take an emotional toll, affecting your outlook and making you more susceptible to anxiety and depression. And just as blood pressure may have an impact your mood, the reverse can also be true: