In 2009 there was a sudden increase in narcolepsy in children. About 2 in 100 people with narcolepsy have a close family member with the condition. Your genes may possibly play a part in the development of narcolepsy. In autoimmune diseases, the body makes similar antibodies (autoantibodies) which attack its normal cells.) It has also been suggested that other things such as a virus may trigger the damage to hypocretin-producing cells in susceptible people. These antibodies help to kill the cells of the germs (bacteria), viruses or other germs causing the infection. (Normally, our body makes antibodies to fight infections - for example, when we catch a cold or have a sore throat. It has been suggested that narcolepsy may be a type of autoimmune disease where there is damage to the cells in the brain that produce hypocretin. In someone with narcolepsy, lack of hypocretin is thought to play a part in the rapid switching between being awake and entering REM sleep. Hypocretin helps to control your sleep-wake cycle. People with narcolepsy have been found to have reduced levels of a neurotransmitter chemical called hypocretin in their brain. You enter REM sleep more quickly than usual and at some unsuitable times. If you have narcolepsy, your sleep-wake cycle is disrupted. Video appointments with qualified counsellors are now available in Patient Access Book now What causes narcolepsy? Weight gain also seems to be more common in people with narcolepsy. You may notice problems with your vision such as blurred or double vision. Sleepiness can also lead to problems with your memory and ability to concentrate. With this automatic behaviour, there is an increased chance that tasks that you are performing go wrong and this can lead to accidents. You might write something unsuitable, or you might say something out of context in a conversation. For example, you may be driving and you may drive to a different, or the wrong, destination. If you are feeling tired and sleepy, there is also a tendency towards automatic behaviour (doing something without really thinking about it and without having any memory of it). It does not affect your breathing and is not dangerous. The paralysis just lasts for a minute or two.

If someone touches you or speaks to you, the paralysis is relieved and you are able to move again. Sometimes it can occur as you are falling asleep. In sleep paralysis, you are conscious but are unable to move your body (called paralysis) when you wake up from sleep. People with narcolepsy are also more likely to sleepwalk. Because of disturbed night-time sleep, even though you may have frequent daytime naps, the total amount of time that you are asleep in 24 hours is about the same as normal. It may seem like you are having a vivid dream. They can happen either as you are falling asleep (hypnagogic) or as you are waking up (hypnopompic). Hallucinations occur when you, for example, see, hear or feel something that is not actually there. Sometimes you can have twitching of your muscles during an attack and some people confuse this with epilepsy. They usually last for under a minute but they can happen several times a day. You still have awareness during the attacks. Emotions such as laughter, elation and anger can trigger cataplexy.

For example, it can mean that you suddenly nod your head, your knees may suddenly give way, you may drop something that you are holding or, in extreme cases, you may suddenly fall to the ground. In cataplexy, you suddenly lose the strength and control in some of your muscles whilst you are awake. About 7 in 10 people with narcolepsy also have cataplexy.

Symptoms of cataplexy