Orthostatic blood pressure is more correctly known as orthostatic hypotension (hypotension is low blood pressure). It is a condition in which a person’s blood pressure drops significantly when changing positions from lying down or sitting to standing up. When we stand up after sitting or lying down, our blood pools in our legs. The direct cause of orthostatic hypotension is failure of the body to react quickly to the position change by shunting blood from the legs back to the heart. With not enough blood to be pumped out of the heart, blood pressure drops. A person with orthostatic hypotension usually becomes dizzy or falls down when standing up too fast. Older people are more at risk, but anyone can have this problem.
Symptoms of orthostatic hypotension can include dizziness, light-headedness, blurred vision, or falling down when trying to stand up quickly, or when getting out of bed too quickly in the morning.
The mechanism that helps the body shunt blood from the legs to the heart is complex and involves many parts. Therefore, there can be many causes, affecting different parts of the process, which can cause orthostatic hypotension.
Dehydration due to exercising or illness causes lower blood volume in the body, which in turn causes orthostatic hypotension. For the same reason, people taking high doses of diuretics (“water pills”) are more at risk for this condition.
Medications such as beta blockers (used for heart disease and high blood pressure), Viagra and certain antidepressants can cause orthostatic hypotension. (This list is not exclusive – other drugs can cause this condition.) Drugs that dilate (widen) the blood vessels and can cause orthostatic hypotension include alcohol and marijuana.
Heart disease that causes the heart to work less efficiently is another cause.
Other causes include (but are not limited to): injuries to the spinal cord, tumors in the spine or brain, severe infections, burns, diabetes, fever, heat (even being in a hot tub), and eating a heavy meal (which sends extra blood to the intestines).
If you have symptoms of orthostatic hypotension, the doctor will measure your blood pressure when you sit (or lie down), stand, and sit or lie back down again. If your blood pressure changes a lot when changing positions, your doctor will diagnose orthostatic hypotension and start looking for the cause.
The treatment of orthostatic hypotension depends on the cause of the condition. For example, if the cause is a medicine you take, your doctor might lower your dose or switch you to another medicine. If the cause is a disease, your doctor will treat it, if possible. Sometimes the cause is very difficult to find, and your doctor may only be able to treat your symptoms.
There are several medications that may help treat very serious orthostatic hypotension. Fludrocortisone helps increase blood volume. Fludrocortisone can cause serious side effects, so close doctor’s supervision is necessary when taking this medicine. Midodrine causes small arteries to narrow, which reduces blood pooling in the legs.
Change positions slowly and gradually.
Avoid standing still for long periods of time.
Wear compression socks (to reduce blood pooling in the legs).
Drink plenty of fluids.
Eat several small meals each day, instead of fewer, bigger meals.
If your symptoms are particularly bad in the morning, consider lifting the head of your bed so that you are not lying flat.