Sleep Disorders

​What causes excessive daytime sleepiness?

Common causes:

• Insufficient sleep: Many people do not get sufficient sleep because of lifestyle choices
• Obstructive sleep apnoea: Refers to cessation of breathing during sleep. Patients may be obese or have blockage of their breathing passages due to problems in their nose or throat.

Uncommon but important cause:

• Narcolepsy: A sleep disorder which is associated with sudden loss of muscle tone, hallucinations and muscle paralysis on waking

People with excessive daytime sleepiness severe enough to cause social or occupational disruption should undergo formal evaluation by a physician. Those with suspected sleep apnoea or narcolepsy usually need to undergo sleep studies.

What causes insomnia?

Insomnia refers to difficulty falling or staying asleep, or a perception of unrefreshing sleep. Insomnia is often related to more than one cause, including psychological and lifestyle factors:

• Excessive or poor managed stress
• Depression and anxiety
• Excessive caffeine consumption
• Poor sleep habits and irregular sleep patterns

Patients with persistent insomnia should be evaluated by a physician to rule out underlying depression, which often presents with early morning waking. Patients who are unable to sleep without sleeping pills may need to be referred to a sleep disorders clinic. Most patients with insomnia can be managed with lifestyle modifications and medication, and do not usually need a sleep study.

What causes abnormal behaviour in sleep?

Abnormal behaviour in sleep often does not require specific treatment unless there is risk of injury, or if the abnormal movements disrupt sleep. Examples of sleep disorders associated with abnormal movements are restless legs syndrome and periodic limb movement disorder, in which excessive leg jerking before or during sleep causes insomnia or excessive daytime sleepiness.

The parasomnias are abnormal behaviours during sleep which can occur in children or adults:

• Sleep terrors
• Nightmares
• Sleep talking
• Teeth grinding
• Sleep walking
• Acting out dreams

A sleep study is frequently required to evaluate these conditions. They must be distinguished from seizures occurring during sleep, which can appear very similar.

Risk factors of sleep disorders

Some sleep disorders such as restless legs syndrome, obstructive sleep apnoea, narcolepsy and the parasomnias have a genetic component and may run in families.

People who have irregular sleep schedules, including shift workers and those who travel across multiple time zones frequently, are also at increased risk of developing sleep related problems.

Lifestyle factors such as excessive caffeine consumption, lack of regular exercise, poor stress management and smoking all contribute to sleep disturbances.

In general, the quality of sleep declines with age. As a result of this, as well as degenerative changes and weight gain which increase with age, sleep related disorders tend to become more frequent as we grow older.