1. Definition
Insomnia is a sleep disorder, described by the difficulty in falling asleep or staying asleep for a long enough period to feel refreshed in the next morning. Patients suffering from insomnia could have their life impacted in several ways, often experiencing fatigue, low mood, difficulty concentrating and decreased performance at school and work.
Adequate sleep depends on a variety of factors and differs between each individual. However, an adult will need approximately 7 to 8 hours of sleep per day to function properly.
Insomnia is categorized by its duration:
– Acute insomnia: brief cases of insomnia caused by changes in lifestyle or environment caused by external circumstances. Most adults will experience this some time in their life; and they normally resolve themselves once the biological clock is corrected.
– Chronic insomnia: described as loss of sleep for more than 3 days a week for at least 3 months. People with chronic insomnia may have to resolve to medication to reset their sleep pattern. Often chronic insomnia will have a link to an underlying disease or condition that requires diagnosis.
2. Epidemiology
Insomnia is the most common sleep disorder in the world. It affects approximately 40 million people in the US alone and 1 in every 3 people in the UK.
Insomnia is particularly more common in women and elderly people. Especially in women, insomnia is more prevalent with the onset of both menses and menopause. Among younger individuals, difficulty falling asleep is often associated with a phase delay syndrome. However, in the elderly, phase advance syndrome results in reports of difficulty initiating sleep, maintaining sleep, and experiencing early morning awakenings.
Patients suffering from insomnia have an increased risk of relating diseases such as sleep apnea and hypoxemia, gastroesophageal reflux disease and neurodegenerative diseases. Additionally, some sleep disorder such as restless leg syndrome and sleep-related breathing disorders can often disrupt sleep and present itself as insomnia.
3. Causes and risk factors
Common causes of insomnia include:
– Stress
– Anxiety
– Depression
– Medical conditions and medications
– A change in environment
– A change in lifestyle, often accompanying with increased age
People with increased risk of insomnia include women, elderly patients, depression sufferers and people in constant travel (jet lag disturbs the regular sleep pattern).
Sources:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1978319/
http://www.mayoclinic.org/diseases-conditions/insomnia/basics/risk-factors/con-20024293
http://www.nhs.uk/Conditions/Insomnia/Pages/Introduction.aspx