The quantity and quality of an individual's sleep change with time. Sleep disorders are relatively more common in older adults, who show more frequent awakening during the night than young adults. Changes in sleep cycles are believed to be caused by emotional stress, physical illness, drugs, and internal body changes (circadian rhythm). Many sedatives and hypnotic drugs, such as benzodiazepines and barbiturates, are used by the elderly to manage their sleep cycles. However, withdrawal from these long-acting agents can be difficult, causing an initial syndrome of insomnia followed by persistent anxiety.
The normal sleep cycle is divided into rapid eye movement (REM) and non-rapid eye movement (non-REM) sleep.
In REM sleep
● Eyes move rapidly
● Body becomes relaxed and immobilized
● Brain becomes more active, close to how it is in wakefulness
● Breathing becomes faster and irregular
● Heart rate and blood pressure increases
● Dreams occur
This sleep cycle usually takes place about 90 minutes after a person first falls asleep. It has a crucial function in the development of the brain and other functions, including mood, dreaming, learning, and memory.
Non-REM is divided into four stages
The first stage is the lightest stage of sleep, and it lasts for around 5-10 minutes of the sleep cycle. This is the transition period between wakefulness and sleep and is characterized by a sense of calmness, slow pulse, respiration, and a decrease in blood pressure.
Stage two constitutes the largest percentage, 45%, of sleep time. During this phase, body temperatures fall, and heart rates begin to slow. If seen on EEG, sleep spindles and K-complexes are visible.
Stage three is the deepest and most relaxed stage of the sleep cycle. It is characterized by slow-wave sleep or the delta waves on an EEG. Heartbeat and breathing decrease to their lowest levels at this stage of sleep. During this period, people become less responsive, and noise and activity in the environment will likely not generate a response. The body starts to repair itself, and the muscles become relaxed.
Stage four of the non-REM sleep cycle is far more intense than stage three. In this stage, the body repairs and regenerates tissue and muscles and works to strengthen the immune system. This stage makes up about 10-15% of sleep.
Most sleep disorders such as sleepwalking, bedwetting, and night terrors occur during this stage.
Symptoms of sleep disorders
● Excessive daytime fatigue and irritability
● Taking naps during the day
● Early morning headaches
● Lack of concentration
● Difficulty in falling asleep
● Loud, persistent snoring
● Choking or gasping for air on lying down
● Restless sleep
● Frequent visits to the bathroom
Sleep disorders are divided into:
● Primary sleep disorders — disorders occurring as a direct result of disturbances in the sleep-wake cycle. These can be further divided into:
● Secondary disorders — disorders occurring as a consequence of other mental conditions such as depression and psychosis or any medical condition e.g., drug abuse or severe pain.
1. Primary insomnia: This is a sleep disorder that isn't directly linked to any other health condition or problem. Instead, it is triggered by emotional stress, anxiety, and hectic work schedules. In this condition, a person cannot sleep, and if they sleep, they do not feel well-rested afterward.
2. Primary hypersomnia: This is characterized by persistent and excessive daytime sleepiness, which is not relieved by napping.
3. Narcolepsy: These are daytime sleep attacks, which are relieved by napping.
4. Breathing-related sleep disorder: This refers to abnormal breathing during sleep, which leads to sleep disruption.
5. Circadian rhythm sleep disorder: In this disorder, a mismatch between a person's circadian rhythm and external sleep-wake demand is seen.
1. Nightmare disorders: This consists of episodes of scary dreams that wake an individual from sleep.
2. Sleep terror disorder: This is characterized by frequent episodes of terror during sleep. One may sit up or scream and appear extremely frightened
3. Sleepwalking disorder: This occurs when one walks or performs other complex motor activity while asleep.
Non-pharmacological methods of improving sleep:
● Establish physical activity in the afternoon and exercise regularly
● Sleep and rise at about the same time daily with no or minimal change in routine
● Avoid taking afternoon naps
● Avoid eating large meals near bedtime, and eat a light snack containing calcium and sugar to help induce sleep
● Sleep in a room that is dark, quiet, comfortable and cool
● Practice muscle relaxation and stress reduction routines like
○ A warm bath or shower before sleeping
○ Evening prayers
○ Reading a book
○ Listening to soothing music
● Lying in bed only when sleepy and not for watching TV
● Avoiding consumption of harmful drugs and beverages which contain nicotine or caffeine
● Maintaining comfortable sleeping conditions with a cozy mattress and pillow
Sedatives and hypnotics are given to patients suffering from sleep disorders. However, these should be taken only under a doctor's prescription because withdrawal from these drugs may lead to tolerance and dependence.