Good quality sound sleep is to fall asleep easily, stay asleep, and feel rested upon waking. There are two essential alternating phases of a typical 90-minute sleep cycle, REM (Rapid Eye Movement) and NREM (Non-REM), each playing a distinct role in rest and recovery. Early sleep cycles have more NREM sleep, and later cycles have more REM sleep. Infants have more REM sleep. The recommended number of hours of sleep varies with age. Adults generally need 7-9 hours of sleep per night, while children and teenagers require more, and infants need even more sleep. Pain, depression, anxiety, stress, exposure to light before bed, sleep and lifestyle factors like lack of exercise, shift work, jet lag, caffeine, alcohol, and substance abuse, apnoea, and other sleep disorders, heart disease, lung disease, and neurological disorders can interfere with sleep patterns. Poor sleep quality leads to difficulty getting up in the morning, daytime sleepiness, tiredness, irritability, depression, anxiety, difficulty concentrating, reduced productivity, feeling hungry more often, with potential for weight gain, and increased risk of heart disease, stroke, and diabetes. Certain medications can affect sleep, while others can be used to treat sleep disorders.
NREM SLEEP: It has 3 stages of depth with slowing of breathing and heart rate, lowering of body temperature, and relaxation of muscles. Deep sleep is the third stage of NREM sleep, characterized by slow, large brain waves called delta waves and minimal muscle activity, where it’s difficult to wake someone up. Muscle repair, regeneration, and growth occur during this stage. It also contributes to memory consolidation and learning. NREM sleep is vital for strengthening the immune system and repairing the body’s tissues and processes.
REM SLEEP: is characterized by increased breathing and heart rate, rapid eye movements behind closed eyelids, increased brain activity with fast and low amplitude brain waves similar to that of a waking state, and is associated with vivid dreaming and paralysed muscles (Atonia) to prevent acting out dreams. REM sleep plays a role in consolidating memories, processing emotional memories, especially fear, and can help regulate mood and reduce the risk of depression. Lack of adequate REM sleep can impair learning, memory, and mood regulation and may increase the risk of developing dementia.
DREAMS AND NIGHTMARES: Dreams are a normal and healthy part of sleep and occur during REM sleep. Dreams can be strange and illogical, and influenced by a person’s experiences, worries, and waking thoughts. They may help process emotions, consolidate memories, and solve problems. Nightmares, or distressing dreams, can cause feelings of despair, failure, helplessness, or danger, and often reflect underlying emotional distress, major life changes, or unresolved trauma. They may help the mind to process difficult emotions, reflect on unresolved issues, or be a symptom of a mental health condition, such as nightmares related to past traumatic events in post-traumatic stress disorder PTSD. Irregular sleep patterns can contribute to more frequent or intense nightmares. The emotional distress caused by nightmares can disrupt sleep, leading to fatigue and can worsen existing mental health conditions or lead to new ones. Some medications, particularly those for anxiety or depression, can increase the likelihood of nightmares. A doctor or therapist can help ameliorate frequent, distressing nightmares impacting daily life.
HORMONES AND SLEEP: Hormones regulate sleep, sleep quality, and duration. Insufficient sleep disrupts the body’s internal clock, leading to hormone imbalances, exacerbating sleep problems. Melatonin (“sleep hormone”) is released in response to darkness and signals the brain to prepare for sleep. Disturbed sleep leads to lower melatonin and elevated cortisol (“stress hormone”) levels, making it harder to fall asleep and stay asleep. Estrogen and Progesterone in women fluctuate during the menstrual cycle, pregnancy, and menopause and can cause night sweats, hot flashes, and difficulty sleeping. Growth Hormone is released during deep sleep and is essential for cell growth and repair. Thyroid hormones, leptin (an appetite regulator), and ghrelin (“hunger hormone”) are also influenced by sleep and can affect sleep patterns. Polycystic Ovary Syndrome (PCOS) in obese women causes irregular periods, higher testosterone, and lower progesterone, worsening sleep apnoea, and sleep difficulties.
SHIFT WORK AND JET LAG: Circadian rhythm is an internal biological clock that regulates the sleep-wake cycle, and is influenced by light, darkness, and social cues. Medications, stress, certain dietary patterns, aging, blindness, or neurological disorders can also affect the circadian rhythm. Circadian rhythm disruption can contribute to mood swings, irritability, anxiety, depression, and an increased risk of metabolic disorders such as obesity, diabetes, and cardiovascular disease. It has also been associated with impaired immune function, increased risk of certain cancers, and even neurodegenerative diseases. Working irregular or rotating shifts can disrupt the natural sleep-wake cycle. Jet lag is a temporary sleep disorder that occurs when your body’s internal clock gets out of sync with the local day/night timings after rapid travel across time zones. Jet lag can cause various symptoms, including daytime fatigue, trouble sleeping, and difficulty concentrating. To minimize jet lag, start shifting your bedtime and wake-up time closer to the time zone you’ll be going to before your trip. At your destination, expose yourself to sunlight in the morning to help reset your body’s internal clock. Drink plenty of water and eat regular meals to support your body’s time adjustment. Consider melatonin or other sleep medication only after consulting your doctor.
YAWNING, MICROSLEEP, AND SIESTA: Yawning is often triggered by fatigue, drowsiness, boredom, or seeing others yawn. Excessive yawning can be due to sleep deprivation, insomnia, narcolepsy, neurological conditions like multiple sclerosis, or side effects of medications. Microsleep refers to brief, involuntary lapses into sleep, typically lasting a few seconds. Symptoms can include droopy eyelids, head-nodding, and a blank stare as the brain isn’t processing information. Microsleep, often associated with sleep deprivation and sleep disorders, poses a serious risk when performing tasks that require attention, such as driving, operating machinery, or performing critical tasks, and is a significant risk factor for accidents due to loss of attention and control. Prioritizing sleep, taking breaks during monotonous activities, and avoiding alcohol and medications that cause drowsiness can help reduce the risk of Microsleep. Siesta is a short nap taken after the midday meal, particularly in warm climates, as a respite from the midday heat and to combat afternoon fatigue, relax, and rejuvenate. A short power nap (20-30 minutes) can boost energy levels, alertness, memory, reaction time, and performance. However, excessively long naps could potentially disrupt nighttime sleep.
SLEEP DISORDERS: These can significantly impact daily functioning, health, and overall quality of life. Common examples include insomnia, sleep apnoea, restless legs syndrome, narcolepsy, and parasomnias. Insomnia is difficulty falling or staying asleep, often leading to daytime fatigue and irritability. Sleep Apnoea is caused by a blockage or narrowing of the upper airway during sleep, disrupting airflow and causing gasps or awakenings. This can be caused by excess weight, enlarged tonsils or adenoids, a thick neck, or a combination of these. Central sleep apnoea is due to inadequate breathing signals from the brain due to various factors. Restless Legs Syndrome (RLS) can occur both when awake and asleep, but is worse when trying to fall or stay asleep. There is an overwhelming urge to move the legs, often accompanied by uncomfortable sensations like tingling, itching, or aching. Some sleep disorders, like insomnia and RLS, can be inherited. Narcolepsy is a neurological disorder characterized by excessive daytime sleepiness, sometimes with sudden muscle weakness (cataplexy). Parasomnias are unusual behaviours or experiences during sleep, such as sleepwalking, sleep terror episodes, or sleep paralysis. Sleep studies (polysomnography) and questionnaires are often used to diagnose sleep disorders. Treatment options vary depending on the type of sleep disorder and may include lifestyle changes, cognitive-behavioural therapy, medications, or medical devices like CPAP machines for sleep apnoea.
REQUIREMENTS FOR GOOD SLEEP: Manage stress and anxiety by regular physical activity, deep breathing, or meditation to calm your mind and promote sleep. Consistent sleep-wake schedule, even on weekends, avoidance before bedtime of physical activity, screen time, large meals, caffeine, and alcohol, calming activities before bedtime like reading, taking a warm bath, or listening to soft music; and a comfortable, dark, quiet, and cool sleep environment, enhance sleep quality. A durable medium-firm mattress and pillow that provides the necessary support and comfort to promote proper spinal alignment, distribute body weight evenly, prevent pain and discomfort, and regulate body temperature, contributes to restful sleep. Mattresses and pillows can release harmful chemicals, impacting indoor air quality, and can lead to various health issues. These chemicals can be avoided by proper ventilation, use of low VOC emissions certified mattresses and pillows, or those made with natural materials, and airing out new mattresses before use. Medications may help with sleep or wakefulness, treat underlying medical conditions, or sleep disorders. Cognitive Behavioural Therapy for Insomnia (CBT-I) can help individuals identify and change negative sleep patterns and beliefs.
Dr. P.S.Venkatesh Rao is a Consultant Endocrine, Breast & Laparoscopic Surgeon, Bengaluru.