What Is Sleep And Insomnia?

Everyone needs sleep because lack of sleep can affect our health and wellbeing. Some people spend enough time in bed, but their sleep is not refreshing. And while occasional restless nights are often normal, prolonged insomnia can interfere with daytime function, and may impair concentration, diminish memory, and increase the risk of substance abuse, motor vehicle accidents, headaches, and depression. In a 2002 survey, the National Sleep Foundation found that 58% of adults have trouble sleeping at least a few nights a week.

What is sleep?

Sleep is one of the bodyТs most mysterious processes. The most significant characteristic of sleep which differentiates it from the waking state is the interruption of perception. A sleeping person does not see or hear. Additionally, sleep is marked by decreased movement of the skeletal muscles, slowed-down metabolism, and complex and active brain wave patterns.

There are two major types of sleep: rapid eye movement (REM) and non-REM sleep:

Rapid Eye Movement (REM) sleep. It comes and goes throughout the night, and makes up about one fifth of our sleep time. During REM sleep, our brain is very active, our muscles are very relaxed, our eyes move quickly from side to side and we dream.

Non-REM sleep. The brain is quiet, but the body may move around. Hormones are released into the bloodstream and our body repairs itself after the wear and tear of the day. There are 4 stages of non-REM sleep:

Pre-sleep - the muscles relax, the heart beats slower and body temperature falls.
Light sleep - we can still be woken easily without feeling confused.
Slow wave sleep - our blood pressure falls, we may talk in our sleep or sleep walk.
Deep "slow wave" sleep - we become very hard to wake. If we are woken, we feel confused.

We move between REM and non-REM sleep about five times throughout the night, dreaming more as we get toward the morning. During a normal night, we will also have short periods of waking. These last 1 or 2 minutes and happen every 2 hours or so. We aren't usually aware of them. We are more likely to remember them if we feel anxious or there is something else going on - noises outside, our partner snoring.

Sleep is an important factor in all our lives. Sleep helps the body restore and rejuvenate in many different ways. Sleep enables the brain to encode new information and store it properly. REM sleep activates the parts of the brain that control learning. The parts of the brain that control emotions, decision-making and social interactions slow down dramatically during sleep, allowing optimal performance when awake.

Sleep enables the immune system to function effectively. Without proper sleep, the immune system becomes weak and the body becomes more vulnerable to infection and disease. During sleep muscle tissue is rebuilt and restored.

Children need much more sleep than adults. Growth hormones are released during sleep, so sleep is vital to proper physical and mental development. Tired children are often cranky, fussy and become easily frustrated and difficult.

What is insomnia?

Insomnia is a term used to describe several types of sleeplessness. With insomnia, you experience a significant lack of sleep on a regular or frequent basis. Insomnia usually takes one or more of the following forms:


Difficulty falling asleep - more common among young people.
Difficulty maintaining sleep (sleeping lightly and restlessly, waking often, lying awake in the middle of the night) - more common in people over 40. In younger people it may be associated with depression.
Waking early and being unable to get back to sleep - this is more common in older people and anyone worrying about something in particular.

Types of Insomnia

There are two broad categories:

Chronic insomnia - lasting for several weeks, months or even years.
Transient insomnia - lasting for a few nights or weeks only, usually connected to a stressful event.

Chronic insomnia

Chronic insomnia is long-term and may last a month, several months, or years. Chronic insomnia may be caused by either a medical problem, a psychiatric problem, a sleep disorder (sleep apnea, restless legs syndrome, etc.), or poor sleep hygiene. Self help may solve the poor sleep habits, but professional help may be necessary for sleep disorders or for underlying medical or psychiatric problems.

Transient/Acute Insomnia

The most common type of insomnia is transient (acute) insomnia. Transient insomnia lasts from one night to a few weeks and is often caused by an emotional or physical discomfort. Typical factors include stress, attempting to sleep in a new place, changes in time zones, changing bedtimes due to shift work, environmental disturbances such as noise, light and temperature.

Insomnia is also classified into primary and secondary insomnia.

Primary insomnia is insomnia that is not caused by other health problems. This is the most common type of insomnia.

Secondary insomnia is a symptom of another underlying condition that causes the insomnia. When you receive effective treatment for the underlying condition, the insomnia usually goes away.

How Much Sleep Do You Need?

The amount of sleep each person needs depends on many factors, including age. Some people find that they only need 5-6 hours of sleep, while others need 10-11 hours for optimal performance. The average adult functions best with 7-8 hours of sleep a night. However, it is important to consider how much sleep you need on an individual basis. The signs of inadequate sleep are low energy levels, drowsiness, irritability, and poor concentration.



Infants and Children. Infants require about 16 hours a day. From 6 months to about 3 years, childrenТs sleep requirement decreases to about 14 hours. Young children generally get their sleep from a combination of nighttime sleep and naps.

Teenagers. Teenagers need about 9 hours of sleep a night. Sleep is crucial for teenagers because it is while they are sleeping that their bodies release a hormone that is essential during their growth spurt.

Adults. For most adults, 7 to 8 hours a night appears to be the best amount of sleep, although the amount ranges from 5 hours to 10 hours of sleep each day depending on the individual.

Pregnant Women. Women in the first trimester of pregnancy, and sometimes throughout pregnancy, need significantly more sleep than usual.

People tend to sleep more lightly and for shorter time spans as they get older, although they generally need about the same amount of sleep as they needed in early adulthood. About half of all people over 65 have frequent sleeping problems, such as insomnia, and deep sleep stages in many elderly people often become very short or stop completely.

Stopping insomnia