(Chicago Tribune) — Dear Mayo Clinic: My mother is 62 and has had very low blood pressure for two years. She was hospitalized with blood pressure that dropped from 200/78 in bed to 60/40 sitting up. What could be causing this and what can be done to treat her?
ANSWER: Your mother has a condition called orthostatic hypotension. It happens when blood pressure falls significantly as a person stands up. Orthostatic hypotension can cause a variety of symptoms; the most common are feelings of dizziness and faintness.
Blood pressure is a measure of the pressure in a person’s arteries during the active and resting phases of each heartbeat. When you stand, gravity causes your blood pressure to fall slightly as blood pools in your legs, lowering the amount of blood circulating back to your heart to pump. Normally, the drop in blood pressure is limited, though, because when you stand your nervous system triggers your blood vessels to narrow and your heart to beat faster. Sometimes, however, those nervous system responses don’t happen the way they should, resulting in large swings in blood pressure from lying down to standing.
Blood pressure is considered normal in adults if it’s approximately 120/80 millimeters of mercury (mm Hg). If the top number, known as systolic blood pressure, is 90 mm Hg or less, or the bottom number, diastolic blood pressure, is 60 mm Hg or less, that is generally considered low blood pressure. Symptoms caused by low blood pressure may include lightheadedness, fainting (also called syncope), blurred vision, tiredness, unsteadiness with walking, headache, confusion, or neck or back pain with walking.
Symptoms of orthostatic hypotension usually get worse in hot weather or when you are dehydrated. Some medications can also increase symptoms of orthostatic hypotension, including blood pressure medications, medications used to treat Parkinson’s disease, antidepressants and bronchodilators, as well as caffeine, alcohol and appetite suppressants.
Treatment for orthostatic hypotension depends on the severity of symptoms. If symptoms are mild, no treatment is typically required. If they are moderate to severe, treatment can be helpful. Symptoms of low blood pressure are often triggered by dehydration, so drinking more water may help. Extra fluids increase blood volume and prevent dehydration. In some cases, adding salt to your diet can help, too. But your mother shouldn’t do that without talking to her doctor first.