Insomnia actually describes the symptoms of disturbed sleep - rather than an illness in itself.
This is usually defined by the duration of the symptoms and the underlying causes.
This article lists 5 common types of insomnia to help you better understand this common condition.
Type #1 - Transient Insomnia This is the most common type and the one suffered by some 58% of adults at some point in our lives.
Transient insomnia is defined as having symptoms which last up to one week.
This can be triggered by a whole host of factors ranging from jet-lag through to medication or even short-term stresses and worries.
While transient symptoms are uncomfortable, there are many short-term treatments for them including relaxation techniques and natural remedies.
The key is to ensure that any symptoms do not become self-perpetuating after a transient episode - for example by starting a pattern of napping or using caffeine to keep you awake during the evenings.
Type #2 - Short-Term Insomnia Symptoms that last between one and three weeks are classified as 'short-term' insomnia.
This is usually long enough for the disturbed sleep itself to become a concern - with the associated risk that this can add to the symptoms themselves.
Stress and anxiety-induced problems with falling asleep often fall into this category.
While the best treatments involve addressing the underlying factors there are several more techniques available.
These include making a proper assessment of your sleeping environment and evening eating habits and also ensuring that lifestyle factors - including health and exercise are not a cause.
Type #3 - Chronic Insomnia The most debilitating type of insomnia is labelled as 'Chronic' This is defined as continuous symptoms which last for more than 3 weeks.
At this point it is usually advised that sufferers seek professional medical advice.
In addition to this there are several home-based treatments possible including keeping a sleeping diary, which will help to identify any patterns or adverse factors in your evening and bed-time routines.
While drugs often relieve the symptoms of chronic insomnia temporarily, these do carry the potential twin risks of addiction and building tolerance.
Type #4 - Mental Illness Insomnia Here we move to a longer lasting category of symptoms which are associated with either depression and changes in brain chemistry associated with other mental illnesses.
Examples of conditions which are commonly accompanied by mental illness insomnia are schizophrenia and bi-polar disorder (known as manic-depressive disorder).
The treatment of the insomnia symptoms in these cases needs to be supervised by a medical professional, especially where this involves medication which may have a cross-effect on medications for the underlying condition itself.
Type #5 - Fatal Familial Insomnia The final type on insomnia is thankfully extremely rare.
It is actually a genetically inherited condition cased by a mutant protein and is always fatal between 7 and 36 months after first symptoms are shown.
While there is a 50 / 50 chance that the child of an 'carrier' parent will inherit this condition, it is not until middle-age that most patients show symptoms - with the average onset being around 50.
Insomnia becomes increasingly marked once this begins, leading to the complete inability to sleep and eventually death.
Fortunately, the main gene responsible has only been identified in 28 families worldwide.