How does insomnia affect the body?

 Anyone who has had a sleepless night can attest to the fact that they don't feel 100% the next day. However, could lack of sleep be having more effect on the body than just leaving a feeling of tiredness?

The brain is the part of the body that is more dramatically affected by insomnia, and many of its everyday functions are inhibited by insufficient rest. While tests have shown that short-term memory on the whole is unaffected by insomnia, those who suffer from it may have a less active working memory, the part of short-term memory involved with processing and storing information and applying it to a task. fMRI scans showed that those with insomnia had lower activity levels in brain regions involved with this working memory compared with control subjects. As well as impacting everyday thinking, lack of sleep can also result in a slowing of mental processes, reduced concentration and, in cases of extreme sleep deprivation, can restrict the transformation of short-term term memories into long-term memory. As well as reducing the efficienct of the brain, a state of prolonged wakefulness means that activity levels of the emotion-processing part of the brain, the amygdala, rise. This increased activity can cause insomniacs to experience higher levels of frustration and anger throughout the day

Over time sleep deprivation can begin to affect hormonal processes, which can further impact sleep quality. Secretions of the stress hormone cortisol rise, resulting in higher levels of anxiety and a faster heart rate. During normal sleep, a hormone is secreted which suppresses feelings of hunger. When sleep is reduced there is more time for the body to produce ghrelin, the hunger hormone, meaning insomnia patients experience heightened appetite. In order to quickly boost energy levels, the body craves foods with a high sugar or salt content, resulting in an observed link between insomnia and obesity.

As sleep cycles become irregular the body's circadian rhythm is affected, meaning that those suffering from too little sleep are likely to experience more erratic peaks and troughs in their energy levels. It is normal to experience a period of lethargy during the day, however, for insomniacs this period is prolonged, making it harder for them to stay awake in the afternoon. At the other extreme, insomniacs may experience stretches of feeling excessively alert, as they become focussed on the pressures of the day and heart rate and adrenaline levels are maintained at a high level.

In the long term, long periods of limited sleep can have drastic effects on the body and a person's performance during activities. If insomnia persists it is important to see a doctor, who can provide advice or medicinal aid for returning to a normal sleeping pattern, giving the body time to repair and relax.