Laughing During Sleep in medical terms is called Hypnogely is quite a common finding especially in infants and is a benign condition which does not require any attention. Majority of cases of laughing when sleeping is due to dreaming during REM sleep. There have been a few cases where laughing when sleeping have been associated with certain sleep abnormalities and in extremely rare cases certain neurological disorders cause laughing when sleeping.[1]
Studies have been conducted to differentiate between physiological and pathological laughing when sleeping. The study was done on people who had a sleep study done at a facility. The study concluded that out of the 10 people who experienced laughing when sleeping, 9 did it during REM sleep. In 1 patient however, laughing during sleep was caused due to sleep disorder.[1]
The study concluded that laughing during sleep in majority of the cases occurs during REM sleep and was related to dreaming. Normally, these dreams are odd and bizarre and people may not take any notice at all when awake. The study also concluded that this was a behavioral response with nothing to worry about[1]
In rare cases where laughing when sleeping occurs due to neurological disorders the pattern of laughing is different from that of physiological laughing when asleep. This article highlights some of the reasons as to why people laugh in their sleep.[1]
Why Do People Laugh In Their Sleep?
Laughing in sleep normally occurs as a result of a funny dream and has no pathological reason to it. Dreaming only occurs when an individual is in deep sleep. This medically is referred to as REM sleep. This is the time when there is no motion in the body and it is at complete rest. In some cases laughing in sleep may wake the individual up.[2]
Since this is rarely reported by people it is difficult to analyze how many people actually have it although it is believed that it occurs quite frequently. A study done on school children showed that around 30% of children had laughed at least once in their sleep in a span of at least three months or more. When a sample was collected from adolescents this number increased to approximately 70%[2]
REM sleep disorder is also one of the causes for laughing in sleep. This is a condition in which the body does not remain in complete rest during deep sleep. As a result of this, people tend to act out on their dreams. This may involve movement of extremities, shouting, and even laughing in sleep.[2]
REM sleep disorder is extremely rare and not more than 1% of people have this condition. It is however more seen in people above the age of 50 and males tend to have it more than females. People with Parkinson or multisystem atrophy are more likely to develop REM sleep disorder than the normal population. Alcohol abuse and withdrawal can also trigger REM behavior disorder.[2]
In extremely rare cases, certain neurological conditions can cause laughing in sleep. Parkinson disease, multisystem atrophy, hypothalamic hamartoma can cause what is termed as gelastic seizures. In this condition the affected individual has uncontrollable bouts of laughing. This may occur at any time but usually happens when the individual is asleep. Hypothalamic hamartoma is congenital in nature and the first symptom of the condition can be observed when the infant is around 1 year of age.[2]
Laughing in sleep is in most cases seen in babies. There is no clear cut reason for it but it is completely harmless and there is nothing to worry about. As a matter of fact, many parents enjoy seeing their baby laughing in their sleep. It only becomes a cause for concern when the baby starts having episodes of uncontrollable laughter along with ot6her behavioral changes.[2]
In conclusion, laughing in sleep is extremely common in both adults and babies, although it is seen more in babies than adults. Dreaming is the most common cause for laughing in sleep in adults. In babies however, there is no clear cut cause for them laughing in their sleep.[2]
In some cases, REM sleep disorder can cause individuals to laugh in their sleep or a neurological disorder like gelastic seizures can be a cause but these are extremely rare and occur in not even 1% of the general population. Otherwise, laughing in sleep is a normal behavior and has no pathological involvement in it.[2]
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