Other common sleep disorders

There are over 70 sleep disorders all of which have the potential to seriously disrupt sleep and to have long-term ill-effects on health. It is therefore important that they are diagnosed and treated as quickly as possible.

Apart from insomnia and sleep apnoea the more common ones are:


The main symptoms of narcolepsy are excessive daytime sleepiness and abnormal REM sleep. Other symptoms often associated with this disorder are sleep paralysis and cataplexy. Cataplexy is characterized by a sudden episode of muscle weakness triggered by emotions.

Typically, the patient's knees will buckle and may give way upon laughing, surprise and or anger. In severe cases, the patient might collapse and become completely paralyzed from a few seconds, up to several minutes. People suffering from narcolepsy will take anywhere between 1-6 naps per day

Restless leg syndrome (RLS)

RLS affects primarily the legs, but is seen in the arms as well. People experiencing restless legs describe it as a very unpleasant "creepy, crawly" sensations that occur in the legs when they are sitting or lying still. Symptoms occur primarily when awake, but they may also be present during sleep. The constant need to stretch or move the legs often prevents a person with RLS from achieving and maintaining sleep. RLS is thought to affect 5-10% of the population, and is more common in older individuals.

Periodic Limb movement disorder (PLMD)

While the movements of RLS are a voluntary response to uncomfortable feelings the movements of PLMD only occur when a person is asleep and are involuntary. Periodic limb movements, usually occur in the legs but can also affect the arms. The movements occur at periodic intervals, typically every 30 seconds. They usually consist of a rhythmic extension of the toes, together with an upward bending of the ankle, knee or hip.

Night terrors and sleepwalking

Both night terrors and sleepwalking arise during NREM sleep and occur mostly in children between the ages of 3 and 5. Treatment is rarely needed and the presence of these usually does not indicate any underlying medical or psychological problems. The child generally grows out of them.


Simply, nightmares are frightening dreams. They arise during REM sleep. They can be caused by stress, anxiety, and some drugs. When nightmares frequently interfere with sleep, treatment with cognitive behavioural interventions is sometimes undertaken (click here to Another important sleep tip - CBT)