New Findings Focus On Diastolic Blood Pressurethe Second Number In Your Blood Pressure Reading
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Of the two numbers that make up your blood pressure reading, the first one typically gets more attention. That’s because as people age, their arteries lose their elasticity, and the inner walls are more likely to accumulate cholesterol-laden plaque. These factors tend to raise systolic blood pressure, a measure of the pressure inside the arteries when the heart contracts to pump blood throughout the body.
Current guidelines suggest that most people should aim for a systolic blood pressure reading of 140 millimeters of mercury or lower. But last year, a widely publicized clinical trial suggested that a target of 120 mm Hg could further reduce the dangers associated with high blood pressure .
Yet reaching that lower target required an average of three blood pressure medications, which resulted in more side effects. Now, two recent observational studies highlight some concerns about blood pressure that’s too low, particularly with regard to diastolic blood pressure. Diastolic blood pressure represents the pressure between beats when the heart relaxes.
Severe Hypotension Related To Shock
While some of the causes of severe hypotension in shock may also cause orthostatic hypotension, the blood pressure drop is much more severe with the formerand it doesn’t return to normal.
The causes of hypotensive shock include:
- Major blood loss
- Severe fluid loss from diarrhea, burns, or overuse of diuretics
- Cardiogenic shock due heart attack, arrhythmia, or pulmonary embolism
- Vasodilatory shock seen in head injury, liver failure, poisoning, or anaphylaxis.
Shock is a medical emergency and you must call 9-1-1 to get medical help.
Common Causes Of Low Blood Pressure
Fertig says low blood pressure may be caused by:
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Dehydration
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Blood loss
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Anti-hypertensive medications
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Hypothyroidism or adrenal insufficiency, because both thyroid hormone and cortisol promote adrenaline, which constricts blood vessels
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Pituitary tumors, which damage the function of regulatory hormones that stimulate the release of thyroid and adrenal hormones
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What Are The Symptoms Of Low Blood Pressure
Low blood pressure often has no symptoms, but can sometimes mean that not enough blood is flowing to your brain or organs. This can cause symptoms such as:
- feeling dizzy, faint or light-headed
- feeling unsteady
- suddenly noticing your heartbeat
- fainting
If you have these symptoms, stop what youre doing and sit down or lie down in case you fall, and drink some water.
Speak to your doctor or nurse if you experience these symptoms. As well as being unpleasant, they could mean youre at risk of having a fall. They could also be a sign of another health problem.
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
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Nerves that contract smooth muscle in the arterioles, thus reducing their diameter
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Hormones Endocrine Function The main function of endocrine glands is to secrete hormones directly into the bloodstream. Hormones are chemical substances that affect the activity of another part of the body … read more that are primarily made by the kidneys
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Certain drugs
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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Managing Low Blood Pressure
Having low blood pressure once in a while isnt likely a cause for concern.
Tell your doctor about any related symptoms. Keep a journal of your symptoms and what you were doing when they began.
This can help your doctor diagnose the cause of your low blood pressure, especially if youve tried making changes to your diet and lifestyle and still arent seeing your BP at a healthy level.
Conditions That Can Cause Low Blood Pressure
Certain conditions can cause long periods of hypotension that can become dangerous if left untreated. These conditions include:
- pregnancy, due to an increase in demand for blood from both the pregnant person and the growing fetus
- impaired circulation caused by a heart attack or heart condition
- dehydration, for example if youre vomiting and cant keep liquids down, or have severe diarrhea
- endocrine disorders, such as diabetes, adrenal insufficiency, and thyroid disease
- autonomic dysfunction, damage to the nerves that control some bodily functions
- prolonged bed rest
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Treatment Of Low Blood Pressure
Unless accompanied by other conditions, low blood pressure is usually easy to treat and does not require much medication. Often, a low blood pressure diet may be prescribed, or a change in lifestyle may become necessary. Common recommendations include:
Increased intake of water: Dehydration can cause an electrolyte imbalance resulting in signs of low blood pressure, and care towards adequate hydration would be important, especially in high temperature situations, during fevers or dysentery.
Increased sodium in diet: Salted nuts, cheeses and cured fish and meats are high in sodium content, and would help stabilize blood pressure in case it is very low. Care must be taken to not overdo it, however, and for a balance to be maintained.
Limiting alcohol consumption: Alcohol consumption can cause fluctuation in heart rate and limiting its consumption for some time will help alleviate symptoms of low blood pressure in otherwise healthy individuals.
Exercise: Light exercises not involving much strain to the body help improve circulation of blood throughout, and keep the heart healthy. In cases of low blood pressure, it is important to be aware of its symptoms such as palpitations and cold skin so that exercising does not aggravate the condition.
Ceasing any aggravating medication:If intake of certain medication is seen to cause dips in blood pressure, your doctor may recommend a substitute for the drug, or even stopping its consumption till pressure is stabilized.
Check Your Blood Pressure
The only way of knowing whether you have low blood pressure is to have a blood pressure test.
All adults over 40 are advised to have their blood pressure checked at least every five years. Getting this done is easy and could save your life. If you have problems with your blood pressure, it is likely your GP will advise more regular checks.
You can get your blood pressure tested at a number of places, including:
- at your GP surgery
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What Are The Symptoms
Many people with low blood pressure don’t have any symptoms.
Symptoms to watch for include:
- Feeling dizzy, light-headed, or faint.
- Feeling sick to your stomach or vomiting.
- Feeling more thirsty than usual.
- Having blurry vision.
- Breathing very fast.
If you have symptoms of low blood pressure, especially dizziness or fainting, call your doctor.
Watch for symptoms of low blood pressure. Tell your doctor when the symptoms happen so he or she can treat them.
What Blood Pressure Range Is Low What’s Normal
Low blood pressure is a condition in which the force of blood pumping through the arteries is lower than normal.
Blood pressure is expressed in two numbers:
- Systolic blood pressure
- Measures the pressure in the blood vessels when the heartbeats
What Are the Blood Pressure Ranges?
Low, normal, elevated, and high blood pressure is often defined in the following ranges:
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How Is Low Blood Pressure Treated
If your blood pressure is naturally low and isnt causing you any problems it probably wont need any treatment. If you have symptoms and your doctor or nurse feels that you would benefit from treatment, they will try to find the cause of your low blood pressure so that they can find the best way to treat it.
The treatments will vary depending on the cause.
- A change in medications. If your GP thinks that your blood pressure is caused by a medication youre taking they might want to try an alternative medication or a different dose.
- Hormone replacement. If your low blood pressure is caused by a change in certain hormones, for example if your adrenal glands have been damaged, you may be referred to a specialist called an endocrinologist. They might prescribe hormone replacement medication.
- Medicines to stimulate your nerves. If you have a neurological condition, you may be given medicines to stimulate the nerves.
- Medicines for low blood pressure. These medicines narrow your blood vessels or expand the volume of your blood to raise your blood pressure. These are very rarely needed, as the treatments listed above and the changes you can make for yourself are usually enough.
What Is Low Blood Pressure/hypotension
Low blood pressure or hypotension is a condition where the systolic and diastolic pressure falls below 90 and 60 respectively. Blood pressure is usually measured in millimetres of mercury, and normal blood pressure is usually slightly less than 120/80 mm Hg.
To have low blood pressure is not always a concern however, chronic hypotension can cause a lack of blood flow to the brain, causing dizziness, blackouts or loss of consciousness, and may even be life-threatening in severe cases.
More often, low blood pressure is a symptom of a different concern, such as plaque build-up, a heart disorder or aging related medical conditions, making it necessary to pay attention to signs of low blood pressure in its initial stages.
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Q What Can I Do To Prevent Low Blood Pressure
Risk Of Injury From Falls
If your blood pressure is low enough, the drop can cause symptoms such as fainting or dizziness.This causes a significant risk of falling since youre not conscious to stop the fall. Additionally, youre not aware of how badly youve injured yourself during a fainting spell. This can lead to serious injuries, such as head trauma from hitting your head.
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Exercise For Low Blood Pressure
Everyday exercise such as a 30-minute walk or light running can serve to improve circulation and alleviate any existing symptoms of low blood pressure. It is best to go with a companion if already a patient of hypotension, in case episodes of blurry vision, giddiness, or fainting happen during these times.
It is necessary to avoid undue stress to the body and sudden, jerky movements through heavy lifting and other strenuous exercise so that the flow of movement is smooth. Discipline and consistency regarding exercise aids the underlying causes of low blood pressure, while alleviating its symptoms as well.
How Can You Prevent Low Blood Pressure
You may be able to prevent hypotension by making changes to your lifestyle and diet, such as:
- Eating fewer carbohydrates and choosing small, healthy meals.
- Staying hydrated and avoiding alcoholic drinks.
- Rising slowly when youve been sitting or lying down.
- Taking a few deep breaths before you change position.
- Wearing compression stockings.
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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.
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
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Low Diastolic Pressure: No Symptoms
“When your systolic blood pressure gets too low, it can manifest as lightheadedness, fainting, and weakness. But low diastolic pressure by itself doesn’t have any symptoms,” says Dr. Paul Conlin, professor of medicine at Harvard Medical School and chief of medicine at the VA Boston Healthcare System.
One of the new studies, which analyzed the medical records of more than 11,000 adults over a period of three decades, found that people who had low diastolic blood pressure were twice as likely to have subtle evidence of heart damage compared with people whose diastolic blood pressure was 80 to 89 mm Hg. Low diastolic values were also linked to a higher risk of heart disease and death from any cause. The findings appeared in the Aug. 30, 2016, Journal of the American College of Cardiology.
Another study, published in The Lancet, involved more than 22,000 people with heart disease, whom researchers grouped according to their blood pressure readings. People with well-controlled blood pressure values were considered the reference group.
Not surprisingly, people with high systolic blood pressure were more likely to experience heart attacks or strokes, be hospitalized with heart failure, or to die compared with people in the reference group. But the same was true for heart attacks, heart failure, and death in people with low blood pressure .
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.
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Serious Injuries And Shock
Low blood pressure can also be caused by serious injuries or burns, particularly if you have lost a lot of blood. This can mean that there is less blood being pumped around your body. Low blood pressure can also occur if you go into shock after having a serious injury.
Other kinds of shock are described below.
Anaphylactic shock
Anaphylactic shock, or anaphylaxis, is caused by an allergic reaction to something – for example, a wasp sting or a peanut. During an allergic reaction, your body produces a large amount of a chemical called histamine, which causes your blood vessels to widen and leads to a sudden, severe drop in blood pressure.
Cardiogenic shock
Cardiogenic shock occurs when your heart cannot supply enough blood to your body, so your blood pressure drops. This can happen during a heart attack.
About Low Blood Pressure
The heart pumps a constant supply of blood around the body. The blood flows through different networks in the body, for example, arteries, veins and capillaries. Blood pressure is a measure of the force of the blood on the walls of the arteries as the blood flows through them.
It’s measured in millimetres of mercury and recorded as two measurements:
- systolic pressure the pressure when your heart beats and squeezes blood into your arteries
- diastolic pressure the pressure when your heart rests between beats
For example, if your systolic blood pressure is 120mmHg and your diastolic blood pressure is 80mmHg, your blood pressure is 120 over 80, which is commonly written as 120/80.
Normal blood pressure is between 90/60 and 140/90. If you have a sustained reading of 140/90 or more, you have high blood pressure . This puts you at greater risk of developing serious health conditions, such as heart attack or stroke.
People with a blood pressure reading under 90/60 are usually regarded as having low blood pressure.
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Changing The Body’s Position
Blood pressure can vary throughout the body due to the direct action of gravity. When a person is standing, blood pressure is higher in the legs than in the head, much in the way that the water pressure at the bottom of a swimming pool is higher than that at the top. When a person lies down, blood pressure tends to be more equal throughout the body.
When a person stands up, blood from the veins in the legs has a harder time getting back to the heart. As a result, the heart has less blood to pump out, and blood pressure may temporarily drop throughout the body. When a person sits down or lies down, blood can more easily return to the heart, and cardiac output and blood pressure may increase. Elevating the legs above the level of the heart can increase return of blood to the heart, which increases cardiac output and raises blood pressure.