A woman yawning while holding a cup of coffee

Many older adults feel fatigued—and often cite this pervasive feeling of tiredness as the main reason they limit their activity. In turn, being too exhausted to see friends or go about your usual activities can mean a decreased quality of life.

Such fatigue has long been dismissed as an expected part of aging, but experts are beginning to push back on this idea.

“I don’t think that’s an adequate expla­na­tion,” says Basil Eldadah, M.D., Ph.D., a program officer in the division of ger­i­at­rics and clinical gerontology at the National Institute on Aging in Bethesda, Md. As scientists develop a deeper ­understanding of what aging is biologically, he says, it has ­become clear that it’s no longer accurate to attribute such symptoms to age.

Here’s what you need to know about possible underlying causes of fatigue as well as strategies to help boost your energy.

Shifting Ideas About Fatigue

Imagine asking two women of the same age how tired they were over the past week. If they both rate their level of fatigue a 7 out of 10, you might conclude that it’s their age. Research that measures fatigue has historically asked this kind of question, Eldadah says, but it’s missing something critical: context.

One woman may be rundown after a week of dealing with chronic health problems and has been too tired for social engagements; the other may be tired because she's gone cycling every morning and dined with friends every other night.

More on Getting the Treatment You Need

Now some researchers are shifting their focus from studying fatigue—how tired people are—to studying what's called fatigability: the level of tiredness people feel in the context of the activities they do. They hope that this provides a more comprehensive measurement and helps unearth more about what can cause this type of exhaustion.

Jennifer Schrack, Ph.D., M.S., an asso­ciate professor in the department of epidemiology at the Johns Hopkins Bloomberg School of Public Health in Baltimore, has helped develop new ways to measure fatigability. By having people walk at the same slow pace on a treadmill, for example, she can deter­mine how tired different people get from ­doing the same task.

Eventually, she says, doing those sorts of tests over the course of many years will help reveal how people tire differently as they get older. 

Many Causes of Exhaustion

Researchers hope to uncover new aspects of fatigue in older adults, but certain conditions are already known to cause ­severe tiredness in people of any age, even those who are well-rested.

They include anemia; heart disease; chronic lung disease; diabetes and other endocrine disorders, such as hypo­thyroidism and ­adrenal insufficiency; kidney disease; liver disease; bacterial or viral infections, such as the flu; rheumatological conditions, such as rheumatoid arthritis and lupus; and neurological conditions, such as multiple sclerosis, concussion, and stroke.

Some of these conditions come with troubling symptoms, but in others—such as anemia—unrelenting fatigue may be the first clue that something isn't right.

Fatigue is a common and often unrec­og­nized symptom of depression, and it has been linked to anxiety, stress, grief, and even boredom. Cancer survivors also seem to tire more easily than others who are the same age, Schrack says, even years after remission.

Many common medications—including antihistamines, beta blockers, and benzo­diazepines—can cause fatigue. There's also what’s called deconditioning: Being out of shape can result in you getting fatigued more easily.

Age itself isn't a cause of fatigue, but “there is a lot of data to show that with advancing age, there seems to be this greater kind of inflammatory state some people have called ‘inflammaging,’” Eldadah says.

This increase in the baseline level of inflammation could relate to fatigue, and researchers are looking into why this may happen with aging.

A slightly elevated inflammation state could be a sign that a disease is brewing but hasn't yet reached the clinical level required for diagnosis, he says. That’s one reason it’s especially important to talk to your doctor about persistent ­fatigue so that you can keep an eye on it.

Tips That May Boost Energy

Certain conditions that cause fatigue ­require a treatment plan developed with a doctor. But for many people, simply becoming more active can help, Schrack says. Just remember that trying to suddenly exercise a lot more than before might not be sustainable.

Instead, Schrack says, try increasing your activity just a little bit each week. It doesn’t have to be traditional exercise, she says. Gradually trying to spend less time sitting can help.

Incorporating activ­ity into your regular life—say, walking to the store instead of taking a bus, or raking leaves—may be easier to stick with than doing a workout. Think of it as breaking up sedentary time within the flow of your day rather than as a task you have to go out of your way to do.

Schrack also suggests making sure all your doctors know about all your medications. If you see several specialists, they might not be aware of all the medicine you take. Telling your doctors means they can better understand—and help you to navigate—side effects such as fatigue.

Limiting caffeine, alcohol, and high-sugar and fried foods can also help, as can making sure you stay hydrated throughout the day. If you’re frequently bored, consider participating in a free activ­ity in your community or looking into ways to parlay your knowledge, skills, or experience into volunteering.

First Things First: Get Some Z's

Many causes of fatigue are unrelated to sleep, but if you’re not getting enough sleep or you suspect that your sleep might not be high-quality, trying to improve it should be the first thing you do to see whether it helps. Here are some places to start.

Set a bedtime. Sleep research strongly suggests that going to bed around the same time every night and waking up around the same time every morning can help.

Light up your day. Exposure to blue light during the day is key to feeling awake. This type of light—ideally from the sun, though also from screens—tells your brain to suppress the hormone melatonin and helps you feel alert. (Remember to use sunscreen if you’ll be spending time outdoors.)

Avoid blue light at night. For the same reason, try to avoid screens at nighttime. If you need to use a computer or smartphone, installing programs like f.lux, dimming screen brightness, using features such as Night Shift (iOS), or wearing blue-blocking glasses may help to reduce exposure to blue light.

Get your eyes checked. While different studies have found different results, it may be that if you have cataracts that haven’t been removed, they could be reducing the necessary blue light you need during the day, thereby disrupting your sleep.

Consider sleep apnea. You may also want to ask your doctor about sleep apnea, which occurs more often in older adults and is marked by snoring and reduced or absent breathing. It’s generally treatable with a CPAP (continuous positive airway pressure) machine.

Limit daytime naps. Long, regular naps may make it harder to fall asleep at night. 

Editor’s Note: This article also appeared in the August 2019 issue of Consumer Reports On Health.