While high blood pressure is a greater risk factor for stroke, there are instances when a drop in blood pressure may increase your stroke risk. There’s also some evidence that people with low blood pressure may have more complications and poorer outcomes after a stroke.
A stroke happens when blood flow to part of the brain is disrupted, which can cause damage to brain cells in the affected area.
High blood pressure (hypertension) is a
It’s also possible that a sudden drop in blood pressure when you rise from sitting or lying down, known as orthostatic hypotension, may
This article will take a closer look at what’s known about the link between low blood pressure and stroke.
Blood pressure is a measure of how forcefully the circulating blood in your body is pressing against the inner walls of your blood vessels.
High blood pressure (hypertension) means that a higher amount of force is being exerted against your blood vessel walls. Low blood pressure (hypotension) means there’s less force being exerted against the walls of your blood vessels.
Over time, high blood pressure can damage blood vessels, causing them to become narrower and stiffer. This can make it easier for fatty material, known as plaque, to build up inside your blood vessels. Blood clots can form in the plaque, which can break away and travel to your brain, resulting in an ischemic stroke, the
Uncontrolled high blood pressure can also weaken your blood vessels, increasing the risk of a rupture in your brain. This is known as a hemorrhagic stroke.
Low blood pressure is typically
What’s considered low blood pressure?
Having low blood pressure means you have lower-than-normal blood pressure. For most adults, normal or healthy blood pressure is usually less than 120/80 mm Hg (millimeters of mercury).
Low blood pressure is generally defined as blood pressure that’s lower than 90/60 mm Hg.
For some people, low blood pressure is typical for them and isn’t a cause for concern. For other people, low blood pressure may be due to a health condition. Or, they may have normal blood pressure most of the time but have sudden bouts of low blood pressure.
Although low blood pressure is less common in people who have an ischemic stroke, there may be instances where a drop in blood pressure may increase the risk of stroke.
For instance, some people, particularly older adults, have a condition known as orthostatic hypotension. This means that there’s a sudden drop in blood pressure when you rise from a sitting or lying down position. As a result, your body has a harder time getting enough blood flow to your brain when you stand up.
Orthostatic hypotension can cause symptoms such as dizziness, lightheadedness, and weakness.
According to a large 2018 study of over 11,000 adults who were monitored for 25 years, the risk of ischemic stroke is twice as high among people with orthostatic hypotension. The researchers found that approximately 15% of participants with orthostatic hypotension experienced an ischemic stroke, compared with 6.8% who didn’t have the condition.
While high blood pressure is a greater risk factor for stroke, there is some evidence that people with low blood pressure may have more complications and poorer outcomes after a stroke.
According to a
- heart failure
- gastrointestinal bleeding
- sepsis (an infection of the bloodstream)
While low blood pressure is considered to be less than 90/60 mm Hg, your blood pressure can fluctuate throughout the day. It can also change depending on whether you’re sitting, standing, lying down, exercising, or feeling stressed.
According to the American Heart Association, low blood pressure is typically only considered
- feeling dizzy or lightheaded
- fast, shallow breathing
- blurred vision
- trouble concentrating
- dehydration or unusual thirst
If you’re concerned about your blood pressure, talk with your doctor about what blood pressure range is healthy for you. If you have low blood pressure, ask your doctor about steps you can take to ensure your blood pressure doesn’t drop too low.
If you have orthostatic hypotension, you may be able to minimize a sudden drop in blood pressure by:
- staying well hydrated
- not skipping meals — make sure you eat 3 meals a day
- not rising too quickly
While high blood pressure is one of the leading risk factors for stroke, a sudden drop in blood pressure may, in some instances, increase your risk of an ischemic stroke — a stroke that’s caused by a blocked blood vessel that supplies your brain with blood.
Some research has shown that people with orthostatic hypotension may have double the risk of ischemic stroke compared to people without the condition. Additionally, some evidence has suggested that low blood pressure may increase your risk of recurrent strokes as well as post-stroke complications. More research is needed to determine the cause.
Low blood pressure is often a treatable condition. Talk with your doctor about whether your blood pressure is in a healthy range and what you can do to minimize your risk of a stroke.