By Dr Anjana Kannankara
Living in a world that is highly demanding, we often sacrifice sleep in an effort to fit everything perfectly into our daily routine. A good night’s sleep is essential for helping the body function at its best. Healthy sleep can help the body better regulate blood sugar levels, keep the immune system functioning properly and even improve the heart health by decreasing stress.
How the body sleeps
Many factors help in preparing the body to fall asleep and wake up. There exists an internal “body clock” that controls when a person is awake and when the body is ready for sleep.
The body clock typically has a 24-hour repeating rhythm called the circadian rhythm. Two processes interact to control this rhythm. The first is a pressure to sleep that builds with every hour from the time the person is awake. This drive for sleep reaches a peak around night, when most people fall asleep.
A compound called adenosine is described to be an important factor linked to this drive for sleep. While awake, the level of adenosine in the brain continues to rise. The increasing level of this compound signals a shift toward sleep. While sleeping, the body breaks down adenosine.
The second process involves the syncing in of the internal body clock with certain cues in the environment. Light, darkness and other cues help determine when to be naturally awake and when to feel sleepy.
The light rays received through eyes signal a special area in the brain that it is daytime. This area of brain helps align the body clock with periods of the day and night. When it gets dark, the body releases a hormone called melatonin. The amount of melatonin in the bloodstream peaks towards evening time. Researchers believe this peak plays a vital role in preparing the body for sleep. Exposure to bright artificial light like that from TV, computers or LED clocks in the late night can disrupt this process, making it hard to fall asleep. As the sun rises, owing to the cues and signals received, the body releases cortisol, a hormone that naturally prepares the body to wake up.
Variations in the rhythm
The rhythm and timing of the body clock change with age. Teens fall asleep later at night than younger children and adults. One reason for this is because melatonin is released and peaks later in the 24-hour cycle for teens. As a result, it’s natural for many teens to prefer late bedtimes and sleep late into the morning than adults.
People also need more sleep early in life, when they’re growing and developing hence newborns may sleep more than 16 hours a day, and preschool-aged children need to take naps.Young children tend to sleep more in the early evening. Teens tend to sleep more in the morning. Also, older adults tend to go to bed earlier and wake up earlier.
The patterns and types of sleep also change as people mature. For example, newborn infants spend more time in REM sleep. The amount of slow-wave sleep which is a stage of non-REM sleep, peaks in early childhood and then drops sharply after puberty. It continues to decline as people age.
Factors causing sleep issues
Sleep problems can be caused by various physical, medical, psychiatric, or environmental factors. Although causes might differ, the end result of all sleep disorders is that the body’s natural cycle of slumber and daytime wakefulness is disrupted.
Short-term or acute insomnia can be caused by life stresses such as job loss or change, death of a loved one, or moving, an illness, or environmental factors such as light, noise, or extreme temperatures.
Long-term or chronic insomnia, which occurs at least three nights a week for a month or longer, can be caused by factors such as depression, chronic stress, and pain or discomfort at night.
A common cause of chronic insomnia is a conditioned emotional response. Persistent thoughts about the sleep problem and behaviours that develop around the sleep problem like sleeping in or napping, ruminating in bed tends to maintain insomnia symptoms.
Other factors that can interfere with sleep may be genetics, varied work hours, medicines that interfere with sleep and also the natural ageing of an individual.
How much sleep is good sleep
The amount of sleep required each day changes over the course of life and varies from person to person. The chart below reflects recent American Academy of Sleep Medicine (AASM) recommendations that the American Academy of Pediatrics (AAP) has endorsed — 4-12 months: 12-16 hours/day (including naps); 1-2 years: 11-14 hours/day (including naps); 3-5 years:10-13 hours/day (including naps); 6-12 years: 9-12 hours/ day; 13-18 years: 8-10 hours/ day; 18 years or older: 7–8 hours/day.
Sleep debt
If a person routinely loses sleep or chooses to sleep less than needed, the sleep loss adds up. The total sleep lost is called his sleep debt.
Some consider quick nap as a way to deal with sleepiness. Naps may provide a short-term boost in alertness and performance but doesn’t provide all of the other benefits of night-time sleep.
Some people try to make up for their sleep debt by sleeping more on their days off than on work days. This can be taken as a sign that they aren’t getting enough sleep. Although extra sleep on days off might help the person feel better, it can upset your body’s sleep–wake rhythm.
Are you in danger?
Bad sleep habits and long-term sleep loss will affect health drastically. Sleeping when the body is ready to sleep is very important.
Sleep deficiency can affect people even when they sleep the total number of hours recommended for their age group. People whose sleep is out of sync with their body clocks such as shift workers or routinely interrupted such as caregivers or emergency responders might need to pay special attention to their sleep needs.
If your job or daily routine limits your ability to get enough sleep or sleep at the right times, talk with your doctor. You also should talk with your doctor if you sleep more than 8 hours a night, but don’t feel well rested. You may have a sleep disorder or other health problem.
Sleep aids
Over-the-counter sleep aids might help temporarily but lifestyle changes are usually the best approach for chronic insomnia. Tolerance to the sedative effects of sleep aids can develop quickly which eventually means the longer they are taken, the less likely they are to make one sleepy. In addition, some over-the-counter sleep aids can cause hangover effect, leaving the person feeling weak and unwell the next day.
Medication interactions and side effects are possible as well, and much remains unknown about the safety and effectiveness of sleep aids, hence any medication should be taken strictly under medical supervision. Various non medical therapies like meditation, yoga, hypnosis or relaxation techniques are also preferred to reduce the stress and anxiety thus enhancing healthy sleep.
(The author is director,
TGL Foundation, and
senior director, FWO)