Fatigue (low energy) may accompany cognitive decline in some people living with Alzheimer’s but not others. Often called dementia fatigue, it occurs in a lot of people who have memory problems or cognitive impairments (trouble thinking), both with and without an actual Alzheimer’s diagnosis.

If you’re the caregiver of a loved one who has Alzheimer’s, here’s what you need to know if they develop dementia fatigue.

1. ‘Dementia Fatigue’ Refers to Tiredness in People With Alzheimer’s

Dementia fatigue is exactly what it sounds like — tiredness or exhaustion in people who have various types of dementia or Alzheimer’s.

Many people who experience this fatigue will want to sleep more. One myALZteam caregiver said they struggled with getting their loved one out of bed each morning: ”He argues with me every day. After sleeping 15 to 17 hours, he says he’s tired.”

Others find that they can’t do as much with their loved one as they used to. Another member shared, “It felt good to be out, as we are pretty limited in what we do now due to hubby’s fatigue.”

People with Alzheimer’s may notice their own fatigue. One person living with Alzheimer’s said on myALZteam, “My health is going downhill, and when I’m sleeping, it is usually 14 hours a day. I wake up tired and stay tired until I nap.”

2. Dementia Fatigue Differs From Sundowning

Sundowning, another common symptom of Alzheimer’s, may be related to fatigue but isn’t the same thing. Sundowning is what health experts call the increased confusion, forgetfulness, anxiety, irritation, or agitation that people with Alzheimer’s experience in late afternoon, during the evening, or at night.

People may become more anxious, pace, have hallucinations, or feel agitated. All of this may interfere with their ability to sleep at night or cause sleep disturbances. If sundowning lowers nighttime sleep quality, it could cause more daytime sleepiness.

3. Changes in the Brain May Cause Dementia Fatigue

Not all fatigue associated with Alzheimer’s is caused by a lack of sleep due to sundowning. Some may be tied to changes in the parts of the brain related to the condition itself. One 2022 study indicated that Alzheimer’s damages the neurons that usually keep people awake. As a result, the study participants wanted to sleep all the time.

Brain changes can lead to problems with the biological clock — the internal clock that tells a person when to wake up and when to sleep. If it gets damaged, a person may never feel like they should wake up, or they may develop a pattern of sleeping and waking at unusual times.

4. Dementia Fatigue May Be Related to Age

In general, both fatigue and increased drowsiness during daylight hours get worse as a person ages. In older adults who have these symptoms, certain brain changes occur. Aging is linked with worsening of Alzheimer’s-associated brain changes, including nerve damage. Specifically, the temporal cortex thins and the hippocampus gets smaller. These changes go along with what researchers see in Alzheimer’s disease, too.

It’s important to note that it’s not clear what causes the exact symptoms. Changes in sleep and fatigue may cause changes in the brain, or changes in the brain may cause fatigue and increased sleepiness. More research is needed to determine exactly how it works in the body.

5. Medications May Cause Fatigue

A number of medications can cause excessive sleepiness. Some drugs may be prescribed as interventions for Alzheimer’s or other conditions. Anti-anxiety medications, antidepressants, antihistamines, and blood pressure medications can cause low energy, sleepiness, and fatigue as side effects.

If your loved one has suddenly developed fatigue, instead of slowly getting more tired over time, it may be time to look over their list of medications with a doctor or a pharmacist to make sure the medicine is not the problem.

6. Dementia Fatigue Can Lead to Poor Nutrition

Some people feel too tired to eat and seem to lose interest in food. “My loved one won’t eat breakfast and just wants to sleep,” one caregiver noted.

When this happens, it can be hard to help a person with Alzheimer’s get the nutrition they need to stay well. If your loved one won’t eat because all they want to do is sleep, talk to their health care team to get the solutions you need.

7. Fatigue Often Worsens as Alzheimer’s Progresses

Fatigue and time spent sleeping or in bed are likely to increase as Alzheimer’s moves from early stages to later stages. Near the end of life, a person living with Alzheimer’s may not get out of their bed or a chair without help. Often, their fatigue and disorientation combine to make movement very difficult.

8. Spending the Day Lying Down Can Cause Bedsores

It’s important to make sure that your loved one doesn’t develop bedsores or other physical ailments that can come from lying in bed most of the day. If you work with medical staff who care for your loved one regularly, they’ll usually take steps to prevent these problems. Otherwise, talk to your loved one’s doctor about how you can ensure they stay healthy even as they sleep more.

9. Your Loved One’s Doctor Can Address Increased Fatigue

Whether your loved one is experiencing new fatigue or has been tired for a while, it’s important to talk to their doctor about it. Their doctor can help you look over their medications, possibly changing out any that could be causing the fatigue.

They can also help you come up with plans for dealing with eating issues, sundowning, and more. Finally, they can help you determine whether your loved one’s fatigue is something you need to try to resolve or if you can simply let them sleep when they want.

Talk With Others Who Understand

On myALZTeam, the social network for people with Alzheimer’s, and their loved ones, more than 85,000 members come together to ask questions, give advice, and share their stories with others who understand life with Alzheimer’s.

Are you wondering about dementia fatigue for your loved one? Have you had to manage this symptom of Alzheimer’s? Share your experience in the comments below, or start a conversation by posting on your Activities page.