What Being Tired Says About Your Health

Feeling run down can be a sleep problem — or an early clue from your body that something else needs attention

Kristen Fischer,

AARP

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Published April 23, 2026

woman in a light blue suit lies face down and exhausted across a dusty-rose-colored sofa against a matching pink wall

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Key takeaways

Feeling tired may be due to poor sleep, but it may also be a sign of a medical, mood or medication issue.
Fatigue can stem from many causes, including sleep disorders, anemia, thyroid disease or depression.
Talk to your doctor if you have persistent or worsening exhaustion.

Feeling unusually run down and exhausted? While it may mean that you need more rest or relaxation in your life, it could also reveal that something more serious is happening with your health.

“Feeling tired can be as simple as not getting enough good-quality sleep, but in adults over 50, it can also be a sign that something else deserves attention,” says Dr. Ronya Green, a family medicine physician from Nashville.

Older adults still generally need about seven to nine hours of sleep per night, so regularly feeling tired shouldn’t just be dismissed as “just getting older,” Green notes.

“Sleep isn’t the whole story,” says Dr. Kristie Hsu, an assistant clinical professor of medicine at UC San Diego. Sleep changes with age, as many older adults naturally fall asleep and wake up earlier than younger adults. But feeling tired can sometimes be your body’s early warning sign of other health issues, so it’s worth talking with your doctor about it, she adds.

Physical or mental fatigue

There is a lot of overlap between physical and mental causes of fatigue, so people shouldn’t feel pressured to figure out whether the cause is one or the other on their own, Green says.

Red Flag Warnings

Is your exhaustion or fatigue something urgent?

Know the red flags that warrant urgent care: chest pain, shortness of breath, fainting or near-fainting, fast or irregular heartbeat, severe pain, unusual bleeding or a severe headache along with fatigue, Green says.

“Physical causes are often more likely when fatigue comes with symptoms such as snoring, waking unrefreshed, shortness of breath, reduced exercise tolerance, swelling, weight change, constipation, fever, pain or medication changes,” she says. Night sweats and bowel habits can also be signs of physical problems, Hsu notes.

Green says mental or emotional causes are more likely when tiredness is tied to low mood, worry, loss of interest, grief, poor concentration or feeling emotionally drained, though these symptoms can coexist with physical illness.

“In older adults, fatigue is often multifactorial, with sleep, mood, medications and medical conditions all playing a role at once,” Green says.

A practical clue: If you are getting seven to eight hours of sleep but still wake up exhausted or if your fatigue is limiting daily activities, you should see your health care provider.

It can be helpful to have a sense of whether the symptom seems more like fatigue or sleepiness, as they differ, notes Dr. Brienne Miner, an internist and assistant professor at Yale School of Medicine with a specialty in sleep medicine.

5 causes of fatigue

Fatigue is one of the most nonspecific symptoms in medicine, Hsu says.

“The potential causes span virtually every organ system and disease category. Because fatigue is so nonspecific, we really have to be detectives,” she says.

Feeling tired can be linked to several issues:

1. Mood disorders

Anxiety, depression and boredom can leave you feeling fatigued, says Dr. Karina M. Berg, an associate professor of medicine at UConn Health’s Center on Aging. Most commonly, if you’re feeling tired without any other concerning symptoms, it can be due to mood issues and nonrestorative sleep, which she says are interrelated. Depression doesn’t always present as sadness, Green notes; it can be a loss of interest or low energy.

2. Sleep issues

If you struggle with sleep, you may feel tired a lot, Green says, noting that insomnia can be a culprit. Sleep apnea, which is underdiagnosed but “very treatable,” can cause fatigue, too, Berg says. Restless legs syndrome can also contribute to feeling tired, Miner points out.

3. Anemia

If fatigue seems to be new, it could be related to anemia, Berg says. This is concerning for older adults, because even mild anemia can raise your risk for frailty, falls and death.

4. Thyroid disease

Hypothyroidism becomes more common with age and often causes fatigue along with weight gain, constipation, dry skin or feeling cold, Green says.

5. Medications

Allergy or pain medications, as well as water pills or stimulants, can lead you to feel tired during the day, Miner notes.

Other physical causes of fatigue can range from heart disease, diabetes, lung disease or infection to chronic kidney disease or liver disease, Green says. Long COVID can be another contributing cause, Hsu adds. Mayo Clinic reports a slew of other causes that include cancer, lupus, nutritional deficiencies and rheumatoid arthritis.

“Often, there is more than one factor contributing at the same time,” Hsu adds.

Pooped? What to do next

If you’re tired for several weeks, need naps more often, can’t do usual activities or wake up unrefreshed even after a full night in bed, that is worth discussing with a clinician, Green explains.

Excessive napping can be a sign of a more serious underlying health problem, including heart disease and dementia, and new research published in JAMA Network Open of more than 1,000 older adults found that sleeping too much during the day — especially in the morning — is linked to higher rates of death.

Your best first step is to see your primary care doctor or internist, Green says. They’ll look at your medical history, review medications and perform a targeted exam.

Before you go to your appointment, Green recommends writing down when the exhaustion started, how often it occurs, how you’ve been sleeping, what medications or supplements you’re taking and if you have symptoms such as shortness of breath, chest pain, weight loss, dizziness, snoring, low mood, memory changes, fever or bleeding. Include details about your patterns with caffeine and alcohol, Hsu adds.

“Those details can help the clinician decide whether the issue sounds more like a sleep disorder, mood disorder, medication effect or medical illness,” Green says.

The doctor will want to know if your fatigue is new, persistent, worsening or interfering with daily life, Green adds. They may order basic blood work to screen for anemia, kidney disease and electrolyte abnormalities such as low sodium, Berg adds. (For more, read 9 Ways to Fight Fatigue and Get Your Energy Back.)

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The key takeaways were created with the assistance of generative AI. An AARP editor reviewed and refined the content for accuracy and clarity.

Kristen Fischer is a contributing writer at AARP based at the Jersey Shore. She has also written for Health, WebMD, and McKnights and is the author of Zoo Zen: A Yoga Story for Kids.