Sleepwalking

The sleeping and walking of our body are regulated by the Sleep Centre in the brain and it is stimulated by the calcium of the blood.

When a person enters sleep, the sleep centre of the brain starts to work in two ways. The first thing is, it blocks off part of the brain so that the will to do anything stops. Such sleep is brain sleep. Secondly, certain nerves in the brain stem are blocked by the sleep centre so that internal and external organs do not function and it is body sleep.
The two types of sleep are connected to have a normal sleep. But sometimes, they are separated and causes sleepwalking.
In sleepwalking only brain sleep occurs and this causes a person to walk about in his sleep. Sleepwalking is also known as somnambulism or noctambulism.
It is not a serious disorder, although people can be injured during sleepwalking.
Sleepwalking is not a sign that something is emotionally or psychologically wrong with a child. It doesn't cause any emotional harm.
Sleepwalking occurs within an hour or two of falling asleep and may last on average between 5 and 15 minutes. It occurs during slow-wave sleep of non-rapid eye movement sleep (NREM sleep) cycles. It typically occurs within the first third of the night when slow wave sleep is most prominent and it occurs only once a night.

Sleepwalking events are common in childhood and decrease with age.  In adults it is less common, and rare in old age. Night terrors are much more common in adult sleepwalkers.
Most obvious sign is getting out of bed and walking around. It is difficult to wake up. Sleepwalking actually can involve a range of other behaviours, including:
sitting up in bed and repeating movements such as rubbing eyes or tugging on pyjamas, walking to bathroom, not responding when spoken to, sleep talking, urinating in undesirable places, cleaning, or as hazardous as cooking, driving, violent gestures, grabbing at hallucinated objects or even homicide.
Sleepwalker's eyes are open but they do not see the same way they do when they are fully awake.

Causes for sleepwalking are sleep deprivation, stress, taking drugs such as sedatives which promote relaxation or sleep, stimulants which boost activity, and antihistamines used to treat symptoms of allergy.

Measures to be taken by a person who has sleepwalking disorder are:
body yoga and meditation can reduce stress and anxiety,
intake of stimulants should be avoided before going to bed,
doors and windows of the bedroom are to be locked and sleeping on the floor is to be preferred.
Finally, adequate sleep is required.