Insomnia is a subjective term describing the perception of disturbed or inadequate sleep. Causes include medical diseases, psychiatric disorders, drugs, behavioural factors, circadian dysrhythmias and primary sleep disorders. Insomnia is common, affecting approximately one-third of the total population, and of these about 10% consider it a chronic problem. Insomnia is more common in females and increases with age. Many people with insomnia resort to ineffective or dangerous self-treatment regimens and the combination of alcohol with non-prescription drugs is common. We have carried out a study on 20 patients with Primary Insomnia and were able to demonstrate significant differences in both descriptive and objective EEG data between those with Primary Insomnia and controls. Careful evaluation of the sleep problem and accurate diagnosis are essential in order to choose the right treatment for an individual patient. When a specific problem is identified (psychiatric, physical, behavioural), then the underlying cause needs to be treated. Insomnia can be treated by either non-pharmacological or pharmacological intervention, and often both are used simultaneously. It is recommended that hypnotic treatments should be used for no more than one month.