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Sleep

Sleep apnea: Why you feel tired after a full night of sleep

If you never wake up feeling refreshed, you might have this dangerous condition.

Woman sitting at desk with laptop, eyes closed
Ghislain & Marie David de Lossy/Getty

You know the consequences of not getting enough sleep: mood swings, crabbiness, cravings, difficulty focusing and sluggishness. And when you don't know why you can't get enough sleep, the symptoms become even more frustrating. The culprits behind sleepless nights range from blue light to parasites -- but you might be dealing with something more serious: sleep apnea.

An estimated 22 million Americans suffer from sleep apnea, a sleep disorder that causes you to momentarily stop breathing while you're asleep. With sleep apnea, your airway becomes blocked when your body relaxes during sleep, limiting your lungs to little air flow.

Characterized by loud snoring and often choking noises, sleep apnea causes your brain and body to become oxygen-deprived, often leading to frequent awakenings throughout the night. Depending on the case, it could happen a few times per night or hundreds of times each night.

This guide goes over the different types of sleep apnea, causes, risk factors and symptoms to help you understand sleep apnea. You'll also learn how to go about seeking a diagnosis and treatment options if you think you may have sleep apnea.

Read more: What's the difference between REM and deep sleep?

Different types of sleep apnea

There are three types of sleep apnea, and the way they manifest in your body is different. But the end result is the same -- all three deprive your body of oxygen.

  • Obstructive sleep apnea is the more common form of sleep apnea that occurs when your throat muscles relax, blocking your lungs from receiving oxygen.
  • Central sleep apnea is less common, and it occurs when your brain doesn't properly signal the muscles in your body that control breathing.
  • Complex sleep apnea syndrome, also known as treatment-emergent central sleep apnea, is the least common of all three. This occurs when someone exhibits signs of both obstructive sleep apnea and central sleep apnea 
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Symptoms of sleep apnea

The most common symptom of sleep apnea is snoring, but snoring on its own isn't always indicative of sleep apnea. Snoring followed by silent pauses, gasping or choking sounds is likely a sign of sleep apnea.

Because sleep apnea wakes you up frequently throughout the night (even if you don't notice it), you can suffer from symptoms of sleep deprivation, such as daytime fatigue, difficulty concentrating, unintentional napping and irritability or mood swings.

Other symptoms include:

  • Feeling tired, even when you thought you had a full night's sleep
  • Insomnia or trouble falling asleep
  • Headaches and migraines
  • Loss of memory
  • Decreased sex drive
  • Nocturia (waking up at night to use the bathroom) 

Complications of sleep apnea

When you have sleep apnea, your body is consistently deprived of oxygen throughout the night. This lack of oxygen can have negative long-term effects on your health.

Sleep apnea has been associated with:

  • Hypertension (high blood pressure) 
  • Cardiovascular disease 
  • Stroke
  • Diabetes 
  • Depression 
  • Metabolic syndrome 
  • Liver problems 

Read more: This one tip will help you sleep better tonight

Causes and risk factors of sleep apnea

An "apnea" is a temporary pause in breathing. In most cases, it's caused by tissue collapsing in the back of the throat (obstructive sleep apnea).

When you fall asleep, the muscles of your upper airway relax. This narrows your airway, making it hard for oxygen to reach your lungs. If you sleep on your back, gravity can exacerbate this narrowing, because your tongue relaxes backward toward your throat.

Central sleep apnea is usually linked to other medical conditions, such as heart disorders and brain damage.

As far as risk factors, many things can influence your likelihood to develop sleep apnea, the most common and significant being excess body weight.

Common risk factors for sleep apnea include:

  • Excess weight: If you have a body mass index (BMI) of 25 or higher, your risk for sleep apnea increases.
  • Large neck circumference: Your risk for sleep apnea is higher if your neck measures 17 inches or more for men, or 16 inches or more for women. This is because a larger neck has more tissue that's liable to collapse during sleep.
  • Age: Sleep apnea can affect people of any age, but it becomes more common when people reach young adulthood and middle age.
  • Gender: More men get sleep apnea than women. For women, the risk of sleep apnea increases as they approach and go through menopause.
  • High blood pressure: Hypertension and sleep apnea commonly coexist.
  • Family history: If a family member has sleep apnea, your risk is higher, because sleep apnea can be inherited.
  • Alcohol use: Drinking alcohol before bed can cause your throat muscles to relax even further.
  • Smoking: Smoking can increase inflammation in your airways
POLYSOMNOGRAPHY

To be diagnosed with sleep apnea, you might undergo a polysomnography test.

AMELIE-BENOIST / BSIP / Getty Images

How do you get diagnosed with sleep apnea?

In most cases, doctors diagnose sleep apnea based on a careful physical exam, sleep evaluation and sleep history. You may not be able to provide a sleep history by yourself, but you can enlist the help of someone who shares your bed or room.

A sleep evaluation usually involves overnight monitoring at a sleep center, where machines measure your breathing and other body functions, such as your pulse, while you sleep. Sometimes, at-home sleep tests are an option. Tests that detect sleep apnea include:

  • Nocturnal polysomnography: During this test, equipment measures the activity of your heart, lungs and brain, as well as your breathing and movement patterns and blood oxygen levels while you sleep.
  • Multiple Sleep Latency Testing (MSLT): An MSLT tests for excessive daytime sleepiness by measuring how quickly you fall asleep in a quiet environment during the day. It's often used to diagnose narcolepsy.  
  • Maintenance of Wakefulness Test (MWT): An MWT measures your ability to stay awake during the day by finding your sleep latency, or how long it takes you to fall asleep. Sleep latencies of less than eight minutes during the day are considered abnormal.
  • Home sleep tests: At-home tests are usually simplified versions of nocturnal polysomnography that measure your heart rate, airflow, breathing patterns and blood oxygen levels.

In some cases, doctors refer patients to sleep specialist or otolaryngologist (also known as an ear, nose and throat or ENT doctor) for further evaluation, which can include a nasal airflow test and an examination to rule out any blockages in your nose or ears.

Your doctor might also refer you to a cardiologist or neurologist to look for causes of central sleep apnea. A neurologist may conduct an electroencephalogram (EEG) to measure brain waves and test for central sleep apnea, while a cardiologist can use an electrocardiogram (ECG) to rule out or confirm any heart complications.

Man in his 30s with sleep apnea sleeping using CPAP

CPAP masks are one of the most common way to treat sleep apnea.

Alina Solovyova-Vincent / Getty Images

How to treat sleep apnea

You can treat sleep apnea a few ways, and many people go through a series of trial treatments to find out what works best for their sleep apnea. Sometimes, it takes takes a series of trials to find the best treatment, and most people end up using a combination of common equipment, machines and therapies to get relief.

Treatment options for sleep apnea include:

Continuous positive airway pressure (CPAP): Most people who seek treatment for sleep apnea start with CPAP. You choose a CPAP mask, which sends a pressurized airflow through your throat to open your airways while you sleep. If you use a CPAP, make sure to keep it clean.

Bilevel positive airway pressure (BiPAP):  Similar to a CPAP, a BiPAP also provides a pressurized flow of air. The key difference is that it provides two different streams -- one as you breathe in, and one as you breathe out.

Chinstrap: Usually used in conjunction with a CPAP, chinstraps help you to stop breathing through your mouth.

Oral appliances: If you don't have severe sleep apnea, you could try custom-fitted oral devices that help keep your airway open. Just make sure to get one from a qualified dentist or orthodontist, not a one-size-fits-all appliance from the internet.

Usually, your doctor won't recommend surgery unless all other options have failed to treat and improve your sleep apnea. Most doctors suggest at least a three-month trial of other options before recommending surgery, which can include nasal reconstruction (such as to fix a deviated septum) or removal of adenoids -- the soft tissue in the back of your throat.