Orthostatic hypotension, low blood pressure on standing, can cause fainting. Learn orthostatic hypotension symptoms and causes and how to prevent them.
When you think about blood pressure being a problem, the first thing that probably comes to mind is high blood pressure, or hypertension. It’s a common and well-known risk factor for heart attack and stroke.
On the other hand, lower than normal blood pressure can be a sign of good health and physical conditioning. Even when a person has blood pressure that is quite a bit lower than average, low blood pressure (hypotension) is often benign — but not always.
If you’ve ever stood up suddenly and felt weak and lightheaded, you may have experienced a type of low blood pressure known as orthostatic hypotension. It’s a condition marked by blood pressure dropping significantly when you become upright quickly.
Orthostatic hypotension symptoms and causes may be temporary and easy to treat. But orthostatic hypotension can be dangerous if it leads to fainting and injury-causing falls. And if it is persistent, it may signal serious problems that need medical attention.
Understanding orthostatic hypotension
Your blood pressure is the measurement of how forcefully blood is flowing in your body. It’s measured with two numbers, representing millimeters of mercury (mmhg). The first, higher number is the systolic pressure — the pressure in your blood vessels when your heart beats. The second number, diastolic blood pressure, is the pressure between heartbeats.
A normal blood pressure is usually considered to be about 120/80, according to the CDC. However, it isn’t necessarily a problem if you have lower than normal blood pressure. In fact, people who consistently have low blood pressure but no signs or symptoms of a health problem (asymptomatic hypotension) simply have low blood pressure that’s normal for them, the National Heart, Lung and Blood Institute (NHLBI) explains.
But other forms of hypotension can cause symptoms ranging from mild and momentary light headedness to severe and life-threatening shock. Orthostatic hypotension is a common and often non-serious type of low blood pressure. It occurs when your body can’t adjust blood pressure and blood flow to your brain fast enough for a rapid upright position change.
Orthostatic hypotension symptoms and causes
When blood pressure falls due to orthostatic hypotension, you’ll likely experience brief dizziness or lightheadedness. In some cases, fainting occurs.
Other symptoms of orthostatic hypotension may include:
- Blurred vision
- Weakness and fatigue
- Feeling confused or disorientated momentarily
- Chest pain
Because the drop in blood pressure lasts only a few seconds to a few minutes, symptoms clear up when you sit or lie down until your blood pressure returns to normal, the NHLBI explains.
The causes of orthostatic hypotension are varied, and some people are at higher risk for the condition than others. For example, seniors and pregnant women are more likely to experience orthostatic hypotension. So are people who have been in bed for a long time (while recovering from surgery, for example) and then feel dizzy when back on their feet and upright.
Bleeding (even giving a blood donation), diarrhea and vomiting, and being over-heated and profusely sweating in hot weather are common causes of a drop in blood volume (hypovolemia) and dehydration – and frequently trigger orthostatic hypotension.
See your doctor if orthostatic hypotension symptoms persist
The reason you feel lightheaded may be obvious if you jump up quickly after sitting in the hot sun for hours without drinking much water, or if you have an upset stomach causing dehydration. But don’t diagnose yourself if you have recurring symptoms of orthostatic hypotension. And contact your doctor immediately if you experience fainting spells.
To diagnose orthostatic hypotension, a doctor typically has the patient stand quickly after sitting or lying down or reclining on a tilt table that automatically moves to an upright position. Then blood pressure readings are taken over a period of three minutes. If systolic blood pressure plummets by 20 points or more, or the diastolic drops at least 10 points, orthostatic hypotension is indicated.
Uncovering what’s causing the problem involves going over your history to see if there are reasons you may be dehydrated or have low blood volume. Certain medications may also be behind orthostatic hypotension. For example, vasodilators (blood pressure drugs that widen blood vessels) and the excessive use of diuretics or laxatives and other types of drugs can cause symptoms of the condition.
Another reason to be checked by your doctor: Orthostatic hypotension may be associated with several health problems, including heart disorders (such as arrhythmias), diabetes, Addison’s disease, and certain neuropathies, the National Institute of Neurological Disorders and Stroke (NINDS) points out.
Bottom line? Most orthostatic hypotension causes and symptoms are easy to spot and treat
If your symptoms of orthostatic hypotension are linked to dehydration, make sure you drink enough fluids during the day, especially water. If symptoms persist, your doctor may advise increasing salt in your diet, too, to increase blood volume and raise blood pressure.
When the problem is linked to a medication, work with your doctor to adjust the dosage or to change or discontinue the drug. And if you’ve been on bed rest for a while due to an illness or injury, elastic support hose, as well as staying hydrated, can help you stand up without dizziness.
While most cases of orthostatic hypotension respond readily to these measures, some people with ongoing symptoms may be treated with a prescription medication, such as midodrine, to raise blood pressure.
January 08, 2020
Janet O’Dell, RN