Sleep plays an important role in our healing, recovery and body functioning. Sleep is essential for us. The brain is very active while we sleep, carrying out important functions for our physical and mental functioning the next day. Our internal body clock operates on a 24-hour cycle, known as the circadian rhythm. This cycle is what makes us get tired as the day goes on.

Sleep disorders are conditions that disturb one’s ability to sleep well regularly. They can negatively impact how well you sleep, when and if you can fall asleep, and how long you can stay asleep. Sleep disorders negatively affect a person’s energy, mood, concentration, decision-making, and general health. Further, not getting enough good quality sleep increases the risk of high blood pressure, heart disease, and other conditions.

There are four stages of sleep:

1. Stage 1 non-rapid eye movement (NREM): light sleep, marking the transition from wakefulness to sleep. Typically, it lasts several minutes.
2. Stage 2 NREM: deeper sleep where our heart and breathing rate slow, muscles relax, and eye movements cease. This is the longest stage.
3. Stage 3 NREM: heart rate, breathing rate, and brain activity reach a low. This stage is important for how refreshed we feel the next day.
4. Rapid eye movement (REM): this is usually when dreaming occurs. Heart rate, breathing rate, and blood pressure increase, and the legs and arms become paralyzed. This stage gets longer as the night goes on and first occurs about 90 minutes after falling asleep. This stage is important for memory consolidation.

Most people have experienced problems with sleeping at some point in their lives, but this does not necessarily mean they have a sleep disorder. Signs you may have a sleep challenge or disorder include:

• Regularly have issues sleeping
• Feeling tired during the day despite having at least 7 hours of sleep
• Difficulty performing normal daytime activities

Symptoms of sleep disorders may include¹:

• Daytime sleepiness
• Difficulty falling asleep at night
• Falling asleep at inappropriate times
• Feeling an uncomfortable urge to move when trying to sleep
• Unusual movements during sleep
• Irregular sleep and wake cycle
• Irregular breathing patterns
• Fatigue and dizziness
• Irritability
• Headaches
• Making frequent errors
• Mental disorders

You should see a doctor if^1,2:

• You regularly have trouble falling asleep
• You regularly have difficulty staying asleep or awake
• You don’t feel refreshed when you wake up
• You need naps during the day to feel rested
• You have unexplained daytime sleepiness
• Sleep problems interfere with your ability to do your daily activities
• You fall asleep while driving, watching TV, or reading
• You are told you snore or gasp while asleep
• You sleepwalk

There are over 100 sleep disorders, but the most common types of sleep disorders are³:

• Insomnia – involves problems falling asleep or staying asleep. It is the most common sleep disorder.
• Obstructive sleep apnea – characterized by repeated breathing interruptions during sleep that cause snoring, gasping, or breathing pauses.
• Parasomnias – disruptive sleep-related disorders where one will experience physical actions or verbal expressions while asleep.
• Narcolepsy – a chronic sleep disorder that affects the ability of the brain to control sleep-wake cycles. People with narcolepsy cannot control when they fall asleep and how long they stay awake.
• Restless leg syndrome – characterized by an urge to move your legs while resting.
• Excessive sleepiness – characterized by extreme grogginess almost every day for 3 months in a row.
• Shift work disorder – develops in people who work at night and can lead to excessive tiredness at work and difficulty getting enough sleep during the day.

Non-24-hour sleep-wake disorder – people with this disorder have circadian rhythms that are more or less than the typical 24 hours.

The cause of sleep disorders depends on the type of sleep disorder. Possible causes may includes¹:

• Other medical conditions (heart disease, lung disease, nerve disorders, pain)
• Mental illnesses (depression, anxiety)
• Medication side effects
• Genetics
• Working night shift
• Caffeine or alcohol before bed
• Low levels of certain brain chemicals

Common general risk factors for sleep disorders include:

• Mental health disorders: 80% of patients with depression experience periods of insomnia.⁴ 42-63% of individuals with anxiety and mood disorders have insomnia complaints.⁵
• Stress: adults with higher levels of stress report getting less sleep than adults with lower levels of stress (6.2 versus 7.1 hours, respectively). 43% of adults report that stress keeps them up at night.⁶
• Night work: 10-40% of people who work nontraditional hours will develop a shift work sleep disorder.⁷
• Family history of sleep disorders: 40-60% of patients with restless leg syndrome had a family history of the disorder. First-degree relatives of someone with narcolepsy have a 10-40-fold higher risk of developing the disorder themselves. Inherited factors likely contribute to 40% of a person’s risk of developing obstructive sleep apnea.⁸
• Gender: Women are 1.3-1.8 times more prone to develop insomnia versus men.⁹
• Age: the prevalence of sleep disorders increases with age. Up to 50% of older adults complain about sleep problems compared to 15.9-22.3% of the general population.¹⁰

Risk factors for insomnia include female sex, family history of insomnia, age >60, depression, anxiety, frequent long-distance travel, stress, working night shift, naps near bedtime, excessive caffeine or alcohol, and smoking.

Risk factors for sleep apnea include male sex, age >40, obesity, family history of sleep apnea, neck size of 17 inches or greater, and chronic sinus problems.

Risk factors for parasomnias include other sleep disorders, neurological disorders, medications, and post-traumatic stress disorder.

Risk factors for narcolepsy include brain injury and autoimmune or neurological disorders.

Risk factors for restless legs syndrome include anemia, end-stage kidney disease, pregnancy, and smoking.

Not all sleep disorders can be prevented, but you can reduce your risk by practicing good sleeping habits. To get better sleep, you should avoid caffeinated drinks, tobacco, alcohol, naps after 3 PM, chocolate, and heavy meals.

There is one tool you can use to assess your risk of developing sleep apnea:

• STOP BANG questionnaire – this is a simple 8-question survey that you can complete on your own online at any time. Factors assessed include snoring, daytime tiredness, breathing during sleep, high blood pressure, body mass index, age, neck size, and gender. Based on these factors, you can determine if you are at a low, intermediate, or high risk of sleep apnea. You should discuss your results with your healthcare provider.¹¹

Early detection of sleep disorders can help restore function, improve daytime performance, and reduce the risk of accidents and developing mental disorders.

To diagnose a sleep disorder, your healthcare professional will first perform a physical exam and ask you questions about your medical history and symptoms. Your healthcare provider may ask you to keep a sleep diary to record your sleeping habits, including when you go to bed, fall asleep, wake up, and nap. You may then be referred to a sleep specialist for an overnight sleep study. This study will monitor and record data about your body and brain activity while you sleep.

Your healthcare provider will let you know if there are any specific instructions you need to follow before a sleep study. For example, you may need to take a shower before arrival, avoid applying any lotions or hair care products, and temporarily stop taking certain medications. Pack an overnight bag like you are staying in a hotel. Typically, sleep studies will take place during your normal sleeping time. On the day of your study, avoid caffeine and alcohol, don’t nap, and stick to your routine. When you get to the facility for your sleep study, you will be guided to your room, where you will change into your pajamas. The staff will then attach sensors to different parts of your body. Let your healthcare team know if you have any adhesive allergies or sensitive skin. You will then be asked to perform a few simple tasks to ensure the sensors are working properly. After this, you are free to relax before you go to sleep. Throughout the night, staff may check on you if a wire comes loose or if you are having a serious problem during your sleep. A camera will record you while you sleep so your doctor can compare your sensor readings to what was happening at the time of certain readings You are allowed to get up and use the bathroom during a sleep study. This may or may not require staff help. Results from a sleep study typically take a few days.¹²

Screening tests for sleep disorders in adults include^13,14,15,16:

• Pittsburgh Sleep Quality Index – assesses sleep quality and habits over the last month.
• PROMIS Sleep Disturbance – evaluates self-reported sleep quality, depth, and satisfaction.
• Epworth Sleepiness Scale – assesses daytime sleepiness.
• Functional Outcomes of Sleep Questionnaire – assesses how sleepiness impacts daily activities and quality of life.
• Athens Insomnia Scale – a self-reported questionnaire that assesses the severity of insomnia.
• Insomnia Severity Index – assesses perceived insomnia severity.
• The Mini Sleep Questionnaire – screens for problems with both sleep and wake.
• Sleep Disorders Symptom Checklist-25 – a self-assessment tool that assesses signs and symptoms of 13 sleep disorders.

Your sleep study will likely include the following components17:

• Apnea/Hypopnea Index (AHI)
  • Normal: less than 5
  • Mild sleep apnea: 5-15
  • Moderate sleep apnea: 15-30
  • Severe sleep apnea: greater than 30
• Arousal – awakening that lasts more than 3 seconds.
• Sleep efficiency
  • Normal: typically greater than 85%
  • Insomnia: typically below 85%
• Sleep latency:
  • Normal: 5-15 minutes
  • Excessive sleepiness: less than 5 minutes
  • Difficulty with sleep initiation: greater than 15 minutes
• Stages of sleep
  • Stage 1: should be 5-15% of total sleep time
  • Stage 2: should be 25-45% of total sleep time
  • Stage 3: should be 20-25% of total sleep time
  • Stage R (REM sleep): should be 20-30% of total sleep time
• Sleep architecture – you should have 4-5 cycles of sleep a night
• Oxygen saturation
  • Normal: 94-100%
  • Abnormal: lower than 80 percent
• Periodic Limb Movement Index (PLMI) 
  • Normal: less than 15

Treatment depends on the type of sleep disorder you have but may include:

• Lifestyle modifications – reducing sugar intake and stress, limiting caffeine, decreasing tobacco and alcohol use, eating a healthy diet, and reaching a healthy weight.
• Improving sleep habits – go to bed and wake up at the same time every day, sleep when sleepy, get out of bed after 20 minutes if you can’t sleep and do a calm activity, only use your bed for sleeping, avoid naps during the day, develop a sleep ritual, take a hot bath 1-2 hours before bed, do not watch the clock, use a sleep diary.
• Cognitive behavioral therapy – learn techniques to help you fall asleep and stay asleep. It may help to reduce sleep anxiety.
• Light therapy – sitting in front of a light box may help your body adjust the amount of melatonin it needs to reset your sleep-wake cycle.
• Medications
  • Sleep aids for insomnia
  • Stimulants or wake-promoting medications for narcolepsy
  • Melatonin supplements
• Modifying other medications that may be impacting your sleep
• Use of a continuous positive airway pressure (CPAP) machine for sleep apnea – this device uses air pressure to keep your airways open while you sleep.
• Oral devices – a device you wear in your mouth to hold your jaw or tongue in a position that keeps airways open.
• Procedures – some patients with sleep apnea may need a procedure if the CPAP or oral devices do not work.
  • Adenotonsillectomy surgery – removal of the tonsils and adenoids.
  • Nerve stimulator implant – can help control the tongue while a patient is asleep.
  • Removal of soft tissue in mouth and throat – increases upper airway.
  • Jaw advancement surgery – moves your jaw forward to increase your upper airway.

Studies have found an association between a spouse’s sleep problems and a partner’s poor health, depressed mood, unhappiness, lack of satisfaction with the relationship, and lack of happiness with the marriage.¹⁸

Studies have also found that when both partners sleep less, they often interact in a more hostile way leading to marital conflict.¹⁹

Sleep disturbances that impact relationships should be discussed with a healthcare professional or marriage counselor. Couples sleep therapy may be recommended if relationship problems are suspected to play a role in a sleep disorder. It’s important to include partners in the treatment of sleep disorders to help enhance relationship satisfaction and quality of life for both the patient and the partner. There may need to be a discussion about sleeping arrangements and the possibility of sleeping apart.²⁰

Sleep disorders can also impact sexual function. Many common sleep disorders are associated with erectile dysfunction and urological disorders. It is important to discuss any sexual issues with your doctor in order for them to optimize your treatment.²¹

Myths about sleep disorders²²:

• Our bodies can get used to a lack of sleep – sleep deprivation has short and long-term negative effects on our brain and body. Accumulation of more serious health problems can occur during persistent sleep deprivation.
• It only matters how long you sleep – sleep duration is an important component, but you should also aim for high-quality, uninterrupted sleep.
• You should stay in bed until you can fall asleep – it’s better to get up and do a relaxing activity.
• Alcohol improves sleep – alcohol can mess up your sleep cycle, cause more sleep interruptions, and worsen sleep apnea and snoring.
• Warm temperatures are best for sleep – people sleep best at 65-68 degrees Fahrenheit.
• There is no problem with sleeping with the lights on – light increases the risk of waking up. It’s best to sleep in a dark room.
• Napping can make up for lack of sleep at night – naps are not long enough for you to progress through the whole sleep cycle.
• Snoring is harmless – snoring may indicate an underlying health condition and could be caused by sleep apnea.

Facts about sleep disorders:

• Most adults need 7 to 9 hours of sleep a night.
• Approximately a third of adults experience insomnia symptoms.
• Sleep apnea affects 2-15% of middle-aged adults and 20% of older adults.
• Greater than 50 million people have a sleep disorder in the United States.
• 30% of adults get less than 8 hours of sleep a night.
• 35% of Americans rate their sleep as poor or only fair.