Orthostatic hypotension (postural hypotension)

Orthostatic hypotension (postural hypotension)

Overview

Orthostatic hypotension — also called postural hypotension — is a form of low blood pressure that happens when standing after sitting or lying down. Orthostatic hypotension can cause dizziness or lightheadedness and possibly fainting.

Orthostatic hypotension can be mild. Episodes might be brief. However, long-lasting orthostatic hypotension can signal more-serious problems. It's important to see a health care provider if you frequently feel lightheaded when standing up.

Occasional orthostatic hypotension is usually caused by something obvious, such as dehydration or lengthy bed rest. The condition is easily treated. Chronic orthostatic hypotension is usually a sign of another health problem, so treatment depends on the cause.

Symptoms

The most common symptom of orthostatic hypotension is lightheadedness or dizziness when standing after sitting or lying down. Symptoms usually last less than a few minutes.

Orthostatic hypotension signs and symptoms include:

Lightheadedness or dizziness upon standing

Blurry vision

Weakness

Fainting (syncope)

Confusion

Causes

When standing from a sitting or lying position, gravity causes blood to collect in the legs and belly. Blood pressure drops because there's less blood flowing back to the heart.

Usually, special cells (baroreceptors) near the heart and neck arteries sense this lower blood pressure. The baroreceptors send signals to the brain. This tells the heart to beat faster and pump more blood, which evens out blood pressure. These cells also narrow the blood vessels and increase blood pressure.

Orthostatic hypotension occurs when something interrupts the body's process of dealing with the low blood pressure. Many conditions can cause orthostatic hypotension, including:

Dehydration. Fever, vomiting, not drinking enough fluids, severe diarrhea and strenuous exercise with a lot of sweating can all lead to dehydration. Dehydration decreases blood volume. Mild dehydration can cause symptoms of orthostatic hypotension, such as weakness, dizziness and fatigue.

Heart problems. Some heart conditions that can lead to low blood pressure include extremely low heart rate (bradycardia), heart valve problems, heart attack and heart failure. These conditions prevent the body from quickly pumping more blood when standing up.

Endocrine problems. Thyroid conditions, adrenal insufficiency (Addison's disease) and low blood sugar (hypoglycemia) can cause orthostatic hypotension. So can diabetes, which can damage the nerves that help send signals that control blood pressure.

Nervous system disorders. Some nervous system disorders, such as Parkinson's disease, multiple system atrophy, Lewy body dementia, pure autonomic failure and amyloidosis, can disrupt the body's ability to control blood pressure.

Eating meals. Some people have low blood pressure after eating meals (postprandial hypotension). This condition is more common in older adults.

Risk factors

The risk factors for orthostatic hypotension include:

Age. Orthostatic hypotension is common in those who are age 65 and older. Special cells (baroreceptors) near the heart and neck arteries that control blood pressure can slow as you age. It also can be harder for an aging heart to speed up to make up for drops in blood pressure.

Medications. These include medications used to treat high blood pressure or heart disease, such as diuretics, alpha blockers, beta blockers, calcium channel blockers, angiotensin-converting enzyme (ACE) inhibitors and nitrates.

Other medications that can increase the risk of orthostatic hypotension include medications used to treat Parkinson's disease, certain antidepressants, certain antipsychotics, muscle relaxants, medications to treat erectile dysfunction and narcotics.

Certain diseases. Diseases that can increase the risk of low blood pressure include some heart conditions, such as heart valve problems, heart attack and heart failure. They also include certain nervous system disorders, such as Parkinson's disease. And they include diseases that cause nerve damage (neuropathy), such as diabetes.

Heat exposure. Being in a hot environment can cause heavy sweating and possibly dehydration, which can lower blood pressure and trigger orthostatic hypotension.

Bed rest. Staying in bed for a long time because of an illness or injury can cause weakness. This can lead to orthostatic hypotension.

Alcohol. Drinking alcohol can increase the risk of orthostatic hypotension.

Complications

Persistent orthostatic hypotension can cause serious complications, especially in older adults. These include:

Falls. Falling as a result of fainting is a common complication in people with orthostatic hypotension.

Stroke. The swings in blood pressure from standing and sitting as a result of orthostatic hypotension can be a risk factor for stroke due to the reduced blood supply to the brain.

Cardiovascular diseases. Orthostatic hypotension can be a risk factor for cardiovascular diseases and complications, such as chest pain, heart failure or heart rhythm problems.

Diagnosis

A health care provider's goal in evaluating orthostatic hypotension is to find the cause and determine treatment. The cause isn't always known.

A care provider might review medical history, medications and symptoms and conduct a physical exam to help diagnose the condition.

A provider also might recommend one or more of the following:

Blood pressure monitoring. This involves measuring blood pressure while sitting and standing. A drop of 20 millimeters of mercury (mm Hg) in the top number (systolic blood pressure) within 2 to 5 minutes of standing is a sign of orthostatic hypotension. A drop of 10 mm Hg in the bottom number (diastolic blood pressure) within 2 to 5 minutes of standing also indicates orthostatic hypotension.

Blood tests. These can provide information about overall health, including low blood sugar (hypoglycemia) or low red blood cell levels (anemia). Both can cause low blood pressure

Electrocardiogram (ECG or EKG). This quick and painless test measures the electrical activity of the heart. During an electrocardiogram (ECG), sensors (electrodes) are attached to the chest and sometimes to the arms or legs. Wires connect to a machine, which prints or displays results. An can show changes in the heart rhythm or heart structure and problems with the supply of blood and oxygen to the heart muscle.

An may not detect occasional heart rhythm changes. Your health care provider may recommend monitoring your heartbeat at home. A portable device, called a Holter monitor, can be worn for a day or more to record the heart's activity during daily activities.

Echocardiogram. Sound waves are used to create pictures of the heart in motion. An echocardiogram can show blood flow through the heart and heart valves. The test can help identify structural heart disease.

Stress test. A stress test is done during exercise, such as walking on a treadmill. People who can't exercise might be given medication to make the heart work harder. The heart is then monitored with electrocardiography, echocardiography or other tests.

Tilt table test. A tilt table test shows how the body reacts to changes in position. It involves lying on a flat table that tilts to raise the upper part of the body. The changes in position mimic the movement from lying down to standing. Blood pressure is taken frequently as the table is tilted.

Valsalva maneuver. This noninvasive test determines how well the autonomic nervous system is working. It requires breathing in deeply and pushing the air out through the lips, as though trying to blow up a stiff balloon. Heart rate and blood pressure are checked during the test.

Treatment

Treatment for orthostatic hypotension is directed at the cause rather than the low blood pressure itself. For example, if dehydration causes orthostatic hypotension, your health care provider may suggest lifestyle changes such as drinking more water. If a medication causes low blood pressure when standing, treatment may involve changing the dose or stopping the drug.

For mild orthostatic hypotension, one of the simplest treatments is to sit or lie back down immediately after feeling lightheaded upon standing. Often, symptoms will disappear. Sometimes, medications are needed to treat orthostatic hypotension.

Medications

If orthostatic hypotension doesn't improve with lifestyle changes, medications may be needed to increase blood pressure or blood volume. The type of medication depends on the type of orthostatic hypotension.

Drugs that may be used to treat orthostatic hypotension include midodrine (Roaten), droxidopa (Northera), fludrocortisone or pyridostigmine (Mestinon, Regonol).

Talk to your health care provider about the risks and benefits of these drugs to determine which one is best for you.

Type of Doctor Department : Internal Medicine Specialists, Cardiologists , and Neurologists