Low blood pressure (hypotension)
Low blood pressure (hypotension)
Low blood pressure, also called hypotension, would seem to be something to strive for. However, for many people, low blood pressure can cause symptoms of dizziness and fainting. In severe cases, low blood pressure can be life-threatening.
Although blood pressure varies from person to person, a blood pressure reading of 90 millimeters of mercury (mm Hg) or less systolic blood pressure (the top number in a blood pressure reading) or 60 mm Hg or less diastolic blood pressure (the bottom number) is generally considered low blood pressure.
The causes of low blood pressure can range from dehydration to serious medical or surgical disorders. Low blood pressure is treatable, but it's important to find out what's causing your condition so that it can be properly treated.
For some people, low blood pressure can signal an underlying problem, especially when it drops suddenly or is accompanied by signs and symptoms such as:
When to see a doctor
Still, it's important to see your doctor if you experience any signs or symptoms of hypotension because they sometimes can point to more-serious problems. It can be helpful to keep a record of your symptoms, when they occur and what you were doing at the time.
Blood pressure is a measurement of the pressure in your arteries during the active and resting phases of each heartbeat. Here's what the numbers mean:
Current guidelines identify normal blood pressure as equal to or lower than 120/80 — many experts think 115/75 is even better.
Although you can get an accurate blood pressure reading at any given time, blood pressure isn't always the same. It can vary considerably in a short amount of time — sometimes from one heartbeat to the next, depending on body position, breathing rhythm, stress level, physical condition, medications you take, what you eat and drink, and even time of day. Blood pressure is usually lowest at night and rises sharply on waking.
Blood pressure: How low can you go?
Some experts define low blood pressure as readings lower than 90 systolic or 60 diastolic — you need to have only one number in the low range for your blood pressure to be considered lower than normal. In other words, if your systolic pressure is a perfect 115, but your diastolic pressure is 50, you're considered to have lower than normal pressure.
A sudden fall in blood pressure can also be dangerous. A change of just 20 mm Hg — a drop from 110 systolic to 90 systolic, for example — can cause dizziness and fainting when the brain fails to receive an adequate supply of blood. And big plunges, especially those caused by uncontrolled bleeding, severe infections or allergic reactions, can be life-threatening.
Athletes and people who exercise regularly tend to have lower blood pressure and a slower heart rate than do people who aren't as fit. So, in general, do nonsmokers and people who eat a healthy diet and maintain a normal weight.
But in some rare instances, low blood pressure can be a sign of serious, even life-threatening disorders.
Conditions that can cause low blood pressure
Medications that can cause low blood pressure
Types of low blood pressure
Low blood pressure (hypotension) can occur in anyone, though certain types of low blood pressure are more common depending on your age or other factors:
Even moderate forms of low blood pressure can cause not only dizziness and weakness but also fainting and a risk of injury from falls. And severely low blood pressure from any cause can deprive your body of enough oxygen to carry out its normal functions, leading to damage to your heart and brain.
Preparing for your appointment
No special preparations are necessary to have your blood pressure checked. You might want to wear a short-sleeved shirt to your appointment so that the blood pressure cuff can fit around your arm properly.
Because some medications — such as over-the-counter cold medicines, antidepressants, birth control pills and others — can affect your blood pressure, it's a good idea to bring a list of any medications and supplements you take to your doctor's appointment. Don't stop taking any prescription medications that you think may affect your blood pressure without your doctor's advice.
Because appointments can be brief, and because there's often a lot of ground to cover, it's a good idea to be prepared for your appointment. Here's some information to help you get ready for your appointment, and what to expect from your doctor.
What you can do
Your time with your doctor is limited, so preparing a list of questions will help you make the most of your time together. List your questions from most important to least important in case time runs out. For low blood pressure, some basic questions to ask your doctor include:
In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment at any time that you don't understand something.
What to expect from your doctor
Tests and diagnosis
The goal in testing for low blood pressure is to find the underlying cause. This helps determine the correct treatment and identify any heart, brain or nervous system problems that may cause lower than normal readings. To reach a diagnosis, your doctor may recommend one or more of the following tests:
Tilt table test
In a tilt table test, you lie on a table that adjusts your body position from horizontal to vertical to simulate standing up. The test can tell your doctor if faulty brain signals are causing low ...
Treatments and drugs
Low blood pressure that either doesn't cause signs or symptoms, or causes only mild symptoms, such as brief episodes of dizziness when standing, rarely requires treatment. If you have symptoms, the best treatment depends on the underlying cause, and doctors usually try to address the primary health problem — dehydration, heart failure, diabetes or hypothyroidism, for example — rather than the low blood pressure itself. When low blood pressure is caused by medications, treatment usually involves changing the dose of the medication or stopping it entirely.
If it's not clear what's causing low blood pressure or no effective treatment exists, the goal is to raise your blood pressure and reduce signs and symptoms. Depending on your age, health status and the type of low blood pressure you have, you can do this in several ways:
Compression stockings (also called support stockings) compress your legs, promoting circulation. A stocking butler may help you put on the stockings. ...
Lifestyle and home remedies
Depending on the reason for your low blood pressure, you may be able to take certain steps to help reduce or even prevent symptoms. Some suggestions include:
Last Updated: 2011-05-19
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