Low Blood Pressure in Elderly People: The Vital Facts You Should Know
By Crystal Lee
| Last updated
Most people are aware that high blood pressure in seniors can lead to serious medical issues, but low blood pressure in elderly individuals gets far less attention. However, blood pressure that drops too low can have equally serious effects on your health. It's important to know the facts so that you can take proper care of yourself.
A low blood pressure reading is not necessarily cause for panic. While high blood pressure is harmful even if you don't know you have it, low blood pressure is generally not a problem unless you start experiencing symptoms like dizziness or blurred vision. If that happens, you need to take action. Symptomatic low blood pressure in the elderly can be very dangerous because it raises the risk of a fall. At its most extreme, it can lead to shock and even death.
This article explains the basic facts about blood pressure, including how it's measured and what the measurements mean. It also describes common symptoms of low blood pressure and outlines a variety of factors that can cause such a condition. And it provides information about different ways that low blood pressure in older adults can be treated or managed.
The information below is not a substitute for individualized medical advice from a licensed healthcare provider. Always consult your physician before making lifestyle changes that may affect your health.
Blood Pressure Basics
Blood pressure (BP) is a measurement of the amount of force being used to keep blood circulating throughout your body. This pressure is essential to ensuring that your organs and tissues get the oxygen and nutrients they need.
Blood pressure commonly rises as we age due to stiffening of the arteries. High blood pressure can be a serious health risk. In fact, in 2017, the American Heart Association and the American College of Cardiology redefined high blood pressure and how it should be managed in older adults. The new blood pressure guidelines for seniors are aimed at encouraging more aggressive treatment at an earlier stage in order to keep blood pressure levels from getting too high.
But sometimes BP levels are actually lower than they should be. Low blood pressure means that the force moving blood around the body is lower than expected.
So, what happens when your blood pressure is low? In some cases, nothing. You may feel fine and require no treatment. But if it gets too low, you might experience low blood pressure symptoms such as feeling lightheaded or dizzy.
If your BP drops dangerously low, key organs (like your brain) may not receive enough blood and oxygen to function properly. In extreme cases, you may go into shock and require emergency medical attention. Severe, prolonged low blood pressure can be fatal if it results in bodily organs being starved of essential nutrients.
How blood pressure is measured and what the readings mean
Blood pressure is expressed as two numbers, with one "over" the other. The first, or top, number is the systolic blood pressure. This indicates the amount of pressure your blood exerts against the walls of your arteries when your heart contracts. The second, or bottom, number is the diastolic pressure, which refers to the amount of pressure in your arteries when your heart refills between beats.
Your healthcare provider typically measures your blood pressure using a stethoscope and an inflatable cuff that wraps around your upper arm. The cuff is inflated until it is tight enough to stop the blood from flowing, then it is slowly deflated. Through the stethoscope, your doctor or nurse will hear the whooshing sound of the blood returning; this is the systolic pressure. The moment the whooshing sound disappears marks the diastolic pressure.
The commonly accepted ideal blood pressure for adults is 120/80 mm Hg or lower.1 (The "mm Hg" represents millimeters of mercury, which refers to the gauges used to measure pressure.) But since blood pressure naturally rises with age, your BP might be higher than that without any cause for concern. For instance, a normal blood pressure reading for an 80-year-old woman could be 134/84 mm Hg.2
So, what is considered low blood pressure in elderly people? Typically, the low blood pressure range is anything below 90/60 mm Hg.3 This is called hypotension. A dangerous blood pressure level is 50/33 mm Hg.2
Keep in mind that only one of the numbers has to be below the healthy range in order to qualify as low blood pressure. So, for instance, if your top number (the systolic pressure) is 90 or less, you may have low blood pressure, no matter what your bottom number is.
Many medical experts believe that the most important number in blood pressure is the top one (i.e., the systolic pressure). That's because research has shown that your risk of heart disease and stroke is greater when you have elevated systolic pressure. However, a recent study found that both types of elevated pressure influence your risk of having a stroke or heart attack.4
A low systolic number means that your organs and tissues may not be getting enough blood and oxygen, but a low diastolic number indicates that there may not be enough pressure in your coronary arteries to adequately nourish your heart.
It's important to understand that your readings can vary depending on factors like your stress level, body position, physical condition, medications, and diet. In fact, your levels can fluctuate as much as 30 or 40 mm Hg over the course of the day.5 They will be lowest when you rest and higher when you exercise or experience stress. That's why, in order to accurately compare readings, it's essential to measure your blood pressure in similar circumstances every time.
Blood pressure is also very individualized. A level that is too low for someone else might be typical (and healthy) for you. However, you should worry about low blood pressure when you experience related symptoms.
Blood pressure vs. heart rate
Blood pressure and heart rate are both important indications of how well your heart is working, but they measure different things. As noted above, blood pressure is the force of your blood flowing through your arteries. By contrast, heart rate (or pulse) is the number of times your heart beats each minute.
In adults, the heart typically beats 60 to 100 times per minute while at rest.6 But as with blood pressure, a healthy heart rate will differ between individuals. For instance, a pulse below 60 beats per minute is slower than normal, but it might not cause any issues for you. (It might even be a sign that you are in really good physical shape.)
However, in some situations, a low pulse means that the heart is not circulating enough blood to satisfy the body's needs. That can cause you to feel dizzy and weak. A pulse in the 30s is a dangerously low heart rate and should be investigated.7
The relationship between blood pressure and heart rate is complex. If you're concerned about your numbers, see your doctor.
Symptoms of Low Blood Pressure in Elderly Individuals
As long as you feel OK, a low blood pressure reading is generally nothing to worry about. Doctors are not usually concerned about a low BP in otherwise healthy individuals.
So, when is blood pressure too low? You should see your healthcare provider if you experience hypotension symptoms such as:
- Blurry vision
- Fainting (known as syncope)
- Confusion or inability to concentrate
- An irregular or rapid heartbeat
- Pale, cold, clammy skin
- Shallow breathing
A condition called orthostatic or postural hypotension is common among seniors. It's when a temporary, sudden drop in blood pressure happens after a rapid change of position, such as when you go from lying down or sitting to standing.
Under normal circumstances, some blood pools in your legs when you stand up, but your body compensates by telling your heart to beat faster. If such compensations are delayed or do not take place at all, your blood pressure can drop rapidly. That can cause you to become dizzy. Some estimates suggest that up to 50 percent of elderly adults experience orthostatic hypotension.8
You may also become dizzy due to a sudden drop in blood pressure after eating, especially if you've had a large meal involving lots of carbohydrates. This is called postprandial hypotension. It, too, commonly affects older adults. It's particularly prevalent among seniors who have disorders that affect the autonomic nervous system, such as diabetes and Parkinson's disease.
Causes of Low Blood Pressure
A variety of factors can explain low blood pressure readings. For instance, dehydration can cause low blood pressure because it reduces blood volume. Diabetes can cause low diastolic pressure but high systolic pressure. And conditions like bradycardia (a very low heart rate) can keep the heart from pumping enough blood to maintain adequate pressure.
Medications are also a common cause of low blood pressure in elderly folks. Drugs that are used to treat high blood pressure, including diuretics, calcium channel blockers, alpha blockers, and beta blockers, can go too far and cause hypotension instead. In addition, some prescription medicines for depression (such as imipramine and doxepin), erectile dysfunction (such as tadalafil and sildenafil), and Parkinson's disease (such as levodopa and dopamine agonists) can trigger low blood pressure.
Other low blood pressure causes can include:
- Hypoglycemia (low blood sugar)
- An underactive thyroid
- Addison's disease (a disorder of the adrenal glands)
- Excessive heat
- Extended bed rest
- Anemia due to lack of vitamin B-12 and folate
- Major blood loss
A sudden drop in blood pressure can be caused by severe infections, anaphylactic reactions, uncontrolled bleeding, or extreme dehydration due to fever, diarrhea, or vomiting. The plunge in blood pressure caused by such factors can be dangerous and even life-threatening.
To identify the cause of your low BP, your doctor may conduct:
Treatment for Low Blood Pressure in Elderly People
If you aren't bothered by symptoms of low blood pressure, treatment is likely unnecessary. After all, a low BP on its own is not usually a problem. In fact, it's often taken as a sign of good health.
But if it's affecting your well-being, you need to take steps to address it. Low blood pressure is treated in the elderly by first determining the underlying cause. If your low BP is a result of your medication regimen, your doctor may be able to adjust your dosages or change your meds. (If you find it difficult to keep your meds organized, a pill dispenser for seniors could help.) If dehydration is the culprit, fluid replacement may solve the problem.
In some cases, you may require medication specifically for your low BP. Two of the most commonly prescribed medicines are fludrocortisone and midodrine. Fludrocortisone is a steroid that causes the body to retain sodium and fluid, thus increasing blood volume and raising blood pressure. Midodrine causes your blood vessels to resist expanding, thereby boosting blood pressure.
However, many people are able to manage their hypotension through diet and lifestyle changes rather than medical interventions. Here are some tips on how you can fix low blood pressure:
Get a Handle on Your Health
Low blood pressure in elderly people has a wide variety of causes and effects. The information above can help you understand the danger signs and take appropriate steps to safeguard your well-being.
- 1 American Heart Association, "Understanding Blood Pressure Readings," website last visited on August 7, 2019.
- 2 Disabled World, "Blood Pressure Chart: Low, Normal, High Reading by Age," website last visited on August 7, 2019.
- 3 Mayo Clinic, "Low blood pressure (hypotension)," website last visited on August 7, 2019.
- 4 New England Journal of Medicine, "Effect of Systolic and Diastolic Blood Pressure on Cardiovascular Outcomes," website last visited on July 30, 2019.
- 5 Medical News Today, "What's to know about low blood pressure?," website last visited on February 18, 2020.
- 6 American Heart Association, "Know Your Target Heart Rates for Exercise, Losing Weight and Health," website last visited on October 15, 2019.
- 7 Cleveland Clinic, "Is Slow Heart Rate Good or Bad for You?," website last visited on August 7, 2019.
- 8 Frontiers in Physiology, "Orthostatic Intolerance in Older Persons: Etiology and Countermeasures," website last visited on July 30, 2019.