Insomnia describes a condition where a person is unable to fall asleep or stay asleep for any length of time, at night, or when they should be sleeping. It’s a term for excessive wakefulness.
Hypersomnia describes the opposite. It’s a term for excessive sleepiness, or increased tendency to fall sleep, when you shouldn’t need to, or want to. In other words, hypersomnia is the constant desire to sleep during the day. It can also be used to describe chronic excessive night-time sleep, for no apparent reason.
Further differences between insomnia and hypersomnia:
Insomnia can be caused by any number of factors. These range from:
- Physiological factors: neurological, illness, diet, alcohol, tobacco, sleep and breathing disorder-related, disrupted biorhythms (e.g. from working at night. This category can also include genetic predisposition and the onset of inherited neurological insomnia.
- Psychological factors: sleep disorder-related, chronic stress and acute anxiety.
- Environmental factors: continuous light, noise, temperature and air quality issues.
Hypersomnia is always a neurological disorder. It can be either a primary condition or a secondary condition – the latter a ‘side-effect’ of some medications. (The term hypersomnia is often incorrectly used to describe fatigue from insomnia or lack of quality sleep, bad diet etc. However, it is different from fatigue in that a person can suffer from hypersomnia even if they are getting plenty of good quality sleep at night.)
What these sleep disorders have in common:
Insomnia and hypersomnia may describe opposing conditions, but they have one major thing in common: both cause excessive sleepiness during the day and an inability to function properly. This can impact heavily on life and work.
This common symptom that has the potential to dramatically affect one’s quality of life on a day-to-day basis and over the long term. Chronic insomnia and day-time sleepiness can therefore seriously impact one’s health over the long term. Both are often reported in diagnosis of sleep and breathing disorders.