“Every time I was awake was painful. I was tired all the time,” one MySleepApneaTeam member said. “I felt like I could just take a nap or sleep anytime, anywhere. No amount of caffeine touches it. Some mornings, I wake up feeling like I’ve literally been hit by a truck.”

Breathing interruptions from sleep apnea and daytime fatigue often happen together. You may feel fatigued even before you realize something is wrong with your breathing at night. Research suggests that fatigue can affect daily life even more than daytime sleepiness.

Let’s look at the connection between sleep apnea and ongoing fatigue, as well as how fatigue differs from general tiredness or sleepiness.

Why Does Sleep Apnea Make You Tired?

Here are some of the reasons sleep apnea can cause fatigue.

Interrupted Sleep

When you have obstructive sleep apnea (OSA), your airway gets blocked while you sleep. The airway may narrow or collapse, causing a stress response that wakes you up many times during the night.

These repeated awakenings prevent deep, restful sleep, leaving you feeling exhausted the next day. “Sometimes, it honestly feels more restful to stay up all night lounging than to sleep a full 12 hours,” one member said.

Low Oxygen

Pauses in breathing prevent the body from getting rid of carbon dioxide. Carbon dioxide builds up while oxygen levels drop. This forces the brain to wake you up briefly so you start breathing again.

What Does Sleep Apnea Fatigue Feel Like?

Sleep apnea fatigue can be hard to explain to someone who hasn’t experienced it. Fatigue may feel like:

• Brain fog — People with OSA and daytime sleepiness may have trouble remembering, paying attention, or focusing.
• Physical exhaustion — The fatigue makes basic tasks like walking the dog or getting off the couch feel very difficult.
• The “wired-and-tired” state — You may feel alert or restless even though you are exhausted. When your body’s fight-or-flight system turns on during sleep, you may continue to feel anxious or on edge during the day. People with sleep apnea also have a higher risk of anxiety and depression.
• Daytime sleepiness or drowsiness — Feeling sleepy before bedtime is normal, but frequent or severe daytime sleepiness may be a sign of a sleep problem. This may look like nodding off during a lunch break or feeling sleepy while driving. Doctors call this excessive daytime sleepiness, and it affects about 4 in 10 people with OSA.

How Does Fatigue Affect Daily Life?

Sleep apnea fatigue can affect more than your energy level. It may make it harder to concentrate at work or school and spend time with loved ones. It can also make you feel irritable.

Some people also feel embarrassed or frustrated when others assume they are lazy, unmotivated, or just not sleeping enough.

Fatigue can also affect your safety. Tell your doctor if you feel drowsy while driving, operating machinery, or caring for children. Daytime sleepiness can raise the risk of car accidents.

Can Treatment Relieve Sleep Apnea Fatigue?

Treating sleep apnea can help relieve symptoms, including fatigue and daytime sleepiness.

Continuous positive airway pressure (CPAP) therapy uses a machine and mask to keep your airway open while you sleep. It’s a common treatment for OSA and can significantly improve daytime sleepiness. Using CPAP over time may also help improve your thinking and memory.

Other treatments for sleep apnea include:

• Oral appliances — These devices help keep your airway open while you sleep.
• Other airway pressure devices — These machines adjust air pressure as you breathe.
• Myofunctional therapy — These exercises strengthen the muscles in your mouth and throat.
• Weight loss — Losing excess weight may reduce pressure on the airway.
• Surgery — Surgery may remove or adjust tissue that blocks the airway.

Why Sleep Apnea Fatigue May Linger After Treatment

Some people may continue to feel tired even when they use their CPAP machine regularly. About 10 percent to 20 percent of CPAP users continue to have daytime fatigue. Several factors may play a role.

Your CPAP May Not Be Working as Well as It Could

CPAP treatment works best when you use it regularly and the mask fits comfortably. If your mask leaks, feels uncomfortable, dries out your nose or mouth, or makes it hard to sleep, you may use it less often.

You don’t have to push through CPAP problems. A sleep specialist or equipment provider may be able to adjust your mask fit, recommend a different mask style, add a humidifier, or review your machine data. Small changes can sometimes make treatment more comfortable and effective.

Another Health Condition May Be Causing Fatigue

Fatigue can have many causes besides sleep apnea, including:

• Anemia or vitamin deficiencies
• Thyroid disorders
• Sleep disorders, such as insomnia or narcolepsy
• Chronic fatigue syndrome
• Autoimmune disorders
• Mental health conditions
• Heart and blood vessel conditions

If your symptoms continue after treatment, your doctor may recommend another sleep study to better understand your breathing during sleep. If your sleep apnea is well controlled but you’re still exhausted, you may need more testing to find another cause.

Lifestyle Habits That May Help

Lifestyle changes can’t replace sleep apnea treatment, but they may help you sleep better and have more energy during the day. Here are some tips:

• Go to bed and wake up at the same time each day.
• Limit alcohol and caffeine close to bedtime.
• Find healthy ways to reduce stress.
• Get regular physical activity.
• Eat a balanced diet.

Gentle movement during the day may also help improve your energy over time, even if fatigue makes exercise feel difficult. Start small with a short walk or light stretching, and talk with your doctor before making major changes to your activity level.

Join the Conversation

On MySleepApneaTeam, people share their experiences with sleep apnea, get advice, and find support from others who understand.

What has helped with your sleep apnea fatigue? Share your story in the comments below.