Insomnia

Insomnia is defined as unsatisfactory sleep, which may mean the sleep is insufficient or of poor quality. Poor quality sleep occurs when the person has difficulty falling asleep, cannot stay asleep or wakes early.

According to the Mental Health Foundation's 'Sleep Matters' report, insomnia affects up to one-third of the population. More women suffer than men, but the incidence increases in both sexes with age. Insomnia can be classed as short-term €“ lasting less than four weeks, or long-term/persistent €“ lasting longer than four weeks.

In around 15 to 20 per cent of long-term cases, the condition is described as 'primary', meaning there is no identifiable cause.

If the symptoms can be linked to, or associated with, another condition, it is termed 'secondary' insomnia. Common causes include:

• Stress and/or anxiety €“ this may be related to numerous factors, including work, financial worries or health concerns
• Poor sleep hygiene €“ e.g. using laptops in bed, eating or drinking too late in the evening or smoking
• Poor sleep environment €“ e.g. the room is noisy, light or the incorrect temperature
• Medical conditions €“ this may include cardiac and respiratory conditions such as bronchitis, asthma or angina as well as gastrointestinal conditions like irritable bowel syndrome or acid reflux. Pain can also disrupt sleep, particularly headaches, injuries and arthritis.
• Incontinence and nocturia (getting up in the night to pass urine) may also disrupt sleep. These conditions commonly occur in patients with diabetes or enlarged prostate glands. Thyroid problems and the side effects of the menopause can also disrupt sleep. In addition, there is a recognised link between insomnia and mental health conditions such as depression, post-traumatic stress disorder and schizophrenia.
• Medication and other substances €“ e.g. prescribed medicines such as antidepressants, epilepsy medication, corticosteroids, NSAIDs and some blood pressure treatments, as well as alcohol, caffeine and nicotine
• Jet lag and shift work €“ both require the body to function during dim light, which the body interprets as time to sleep. This can induce sleep during the day.

Insomnia sufferers often find it useful to keep a sleep diary that records the time they go to bed and get up, the number of times they wake during the night and how tired they feel during the day, along with their dietary and lifestyle habits. This information can be a useful starting point for managing their symptoms.

Obstructive sleep apnoea

Obstructive sleep apnoea (OSA) is a relatively common condition, particularly among men aged 30 to 60 years old. According to NHS Choices, an estimated four per cent of middle-aged men and two per cent of middle-aged women have OSA. However, there are thought to be many undiagnosed cases.

In OSA, the walls of the throat relax and narrow during sleep, causing repeated interruption to the person's breathing. As a result, oxygen levels in the blood fall, which triggers the brain to wake the person up. This may occur many times during the night, resulting in poor quality sleep and drowsiness the following day. OSA most often occurs in people who are overweight or obese, or who have a large neck or an unusual structure in the neck such as a narrow airway, a small lower jaw or large tonsils, adenoids or tongue.

Nasal polyps or a deviated septum in the nose also increase the risk of OSA, as do taking sedative medicines, and smoking or drinking alcohol before sleep. There may also be a genetic element.

The most common symptoms of OSA include snoring, noisy or laboured breathing, and repeated periods where breathing is interrupted by gasping or snorting. Sufferers may feel drowsy the following day, have poor memory or difficulty concentrating, and be more prone to headache, mood swings, irritability or even depression.

Restless leg syndrome 

According to NHS Choices, restless legs syndrome (RLS), or Willis-Ekbom disease, affects around one in 10 people in the UK at some point in their lives. Women are twice as likely to suffer as men and symptoms commonly appear in middle age. Sufferers describe an unpleasant crawling or creeping sensation in their feet, calves and thighs, resulting in an overwhelming desire to move their legs.

Symptoms are often worse in the evening and may include involuntary jerking or twitching of the limbs. RLS ranges from mild, occasional symptoms to severe cases that occur on a daily basis.

In the majority of cases there is no obvious cause, although doctors believe there may be a link to how the body processes the chemical dopamine. Some sufferers have an underlying health condition such as iron deficiency anaemia or kidney failure. Around one in five pregnant women suffer in the last trimester of pregnancy.

However, symptoms often disappear after the birth. Sufferers may benefit from practising good sleep hygiene, regularly exercising during the day and quitting smoking.

Narcolepsy 

Narcolepsy affects both sexes and usually begins during adolescence or young adulthood. Sufferers may find it difficult to function due to extreme tiredness and may even fall asleep while eating or talking. Other symptoms may include muscle weakness (cataplexy) while awake, and hallucinations and sleep paralysis while asleep.

The exact cause is unknown, but researchers believe that sufferers have low levels of hypocretin, a chemical in the brain that promotes wakefulness. Some sufferers may have a family history of the condition, while other cases may be linked to infections, brain injuries or autoimmune disorders.