Insomnia is difficulty in getting to sleep or staying asleep. Insomnia contributes to daytime problems such as tiredness, fatigue, excessive sleepiness and feeling unrefreshed upon waking. It is a common complaint, with about one third of people saying they have had insomnia in the preceding year and one in ten people having a chronic problem.

Sleep acts to conserve energy. It is restorative, protective, instinctive, adaptive and is a necessary part of our daily activities so that we can feel refreshed and energetic to deal with life’s changes.

On average people require eight hours’ sleep per day. There are wide variations in individual sleep needs with some people being able to get by on as little as 3 or 4 hours without feeling any ill effects (short sleepers), while others need up to 12 hours sleep per day in order to feel refreshed (long sleepers), Usually, if a person feels well throughout the day, then no matter how little sleep they are getting at night, they are getting ‘enough’.

What happens when you don’t sleep properly?
Not getting enough sleep can mean you don’t sleep for long enough or the quality of your sleep is poor. Quality of sleep can be difficult to establish and sometimes requires further sleep investigations because we often unaware of how well we sleep. For example, small amounts of alcohol and heavy snoring can fragment sleep without you knowing. Sometimes, no amount of extra sleep will compensate for the poor quality.

Nevertheless, sleep deprivation tends to lead to similar problems in most people, Concentration, short-term memory and reasoning are related to the quality and quantity of sleep. People often feel unable to function properly after a poor night’s sleep and complex tasks requiring lateral thinking are affected. Performance of self-placed tasks deteriorates the longer a person suffers sleep deprivation. Boring and repetitive tasks are likely to be most affected and perhaps related to decreased attention during these times.

Accidents may be linked to these changes in your mental state when you are sleep-deprived. For example, the frequency of road accidents increases in the early hours of the morning and the middle of the afternoon - times that correspond with the common patterns of sleepiness throughout the day.

Although sleep deprivation leads to lethargy, there is little evidence that it results in immediate physical damage. On the other hand, feelings of tiredness and fatigue can affect mood state, sometimes leading to irritability, depression and a tendency to become more angry than usual. There may also be a greater tendency to give up on tasks, perhaps related to reduced motivation.

It is important to remember that these symptoms are not always due to a sleep problem and can also be caused by other medical or psychiatric conditions.

Different types of insomnia
True primary insomnia caused by dysfunction of the sleep mechanisms in the brain is uncommon but may develop at any age. Sometimes this is associated with high levels of anxiety and life styles.

On the other hand, secondary insomnia is common, often associated with physical illness, chronic pain, substance use or misuse (including alcohol) and psychiatric conditions. Changes in diet, levels of anxiety and depression and the sleeping environment can also affect sleep.

Sometimes other primary sleep disorders such as nightmares or night terrors (especially in children) can also lead to insomnia.