A child's scream breaks the silence of the night. As the parent runs into the room and attempts to comfort the child, the child begins to fight the parent off -- kicking, screaming, yelling and biting.

This horrific picture occurs in about 200,000 homes in the United States each night. What is it that makes these children act out in such a manner? It is a common sleeping disorder called "sleep terrors." According to the National Sleep Foundation, about 38 percent of all children will experience a period in which sleep terrors occur. But why? And what can a parent do?

According to Mosby's Medical, Nursing and Allied Health Dictionary, sleep terrors are "characterized by repeated episodes of abrupt awakening, usually with a panicky scream, accompanied by intense anxiety, confusion, agitation, disorientation, unresponsiveness, marked motor movements and total amnesia concerning the event."

The disorder is most usually seen in children between the ages of 2 and 12, is more common in boys than girls and has a wide variable of frequency.

"The child with sleep terror will suddenly and abruptly wake up with a shriek, scream or yell," says Dr. Stephen Sheldon, director of the sleep medicine center at Children's Memorial Hospital in Chicago. "The child's actions will only get worse if the parent tries to soothe them. The child may be mumbling and speaking bizarrely or may seem in an absolute panic. Their heart will be beating faster, they will be breathing faster and may be sweating. The event usually last for a minute or two and then the child will go back to sleep, never remembering the event. These are called sleep terrors only because they terrify the parents. The children are really not dreaming; they are in a very deep sleep."

Brette Sember's 8-year-old daughter had sleep terrors between the ages of 3 and 6.

"She would often get up and walk around or just cry and scream in her bed," says Sember, of Clarence, N.Y. "It was as if she did not hear or see us, even though her eyes were open. Nothing we did had an impact on her when it was happening. It really was very upsetting for us as parents. We began to talk to her about it at times but she never had any memory of it."

Sleep terrors are the result of an immature sleep or arousal system of the child, according to the National Sleep Foundation. When a child's sleep system is immature, they do not spend as much time in REM -- also known as the dream state -- and may spend most of their sleep hours in between the arousal state and deep sleep. The arousal state of sleep is the period in which people often report that the environment around them influences their "dreams." If a noise is heard, the noise becomes part of the thoughts of the sleeper. As a result, if a child's arousal system is immature, they may become aroused quickly or abruptly by their environment, Sheldon says. However, these children will not fully awaken but will still respond to whatever it is that aroused them resulting in what is known as a sleep terror.

"It's a maturation problem," says Sheldon. "The arousal system and the sleep system just have to match up with one another to allow the child to maintain a deep sleep or to wake up completely when aroused."

Several factors can play a part in the intensity and frequency of sleep terrors. Sheldon says a child is more likely to have sleep terrors if they are extremely fatigued, under stress, depressed or has had a recent traumatic experience. Influences such as these are called "stressors." Oftentimes identifying the stressor of a child's sleep terrors is the first step to reducing their occurrence.

"As stressors play a big part in how often a child suffers from sleep terrors, it is important to attempt to identify as many as possible," says Sheldon. "Oftentimes stressors are easy to identify -- fatigue, a bully at school, a divorce or a natural disaster. Other times it is very difficult to identify them and it may take a little more investigative work. When a stressor cannot be identified parents may want to consider keeping a journal for their child including things that happen during the day, what they watch on television, who they are with, what they do, etc. The journal can then be taken to the family pediatrician who may be able to see a pattern that the parents may not offering clues to a child's sleep terror occurrences."

Shelley Haggert's daughter was 3 when she started having sleep terrors.

"She would suddenly start screaming after she'd been asleep for a few hours but she wouldn't be awake," says Haggert, of Windsor, Ontario, Canada. "Then all of a sudden, she'd just stop screaming, lie down and close her eyes. She never had more than one per night and not every night. The nights when she was particularly tired, she was more likely to have one."

According to Sheldon, occasional occurrences of sleep terrors are very common and do not require intervention of any kind. However, children who have nightly occurrences for one month or more or who have multiple episodes a night should be evaluated by both a pediatrician and a sleep disorder clinic.

"Nightly or multi-nightly occurrences of sleep terrors are not of the norm," says Sheldon. "If a child has consistent, frequent sleep terrors or there is something unusually or atypical about the spells then the child needs to be evaluated. Intervention for sleep terrors usually begins at the pediatrician -- this is where a sleep diary or journal will be beneficial to help identify stressors. The pediatrician can refer the child to a sleep disorder clinic where further evaluations can be completed."

In most cases, treatment is not necessary for the management of sleep terrors. However, if a child has severe sleep terrors or the frequency of the episodes increases dramatically, it may be recommended that the child be placed on a mild sedative medication at bedtime.

"Typically, the episodes of sleep terrors go away on their own," says Sheldon. "There are cases when a child needed medical intervention and medication to manage the terrors, but these cases are few and far between. If the parent consults their pediatrician or has the child evaluated at a sleep disorders clinic, the stressors that influence a child's terrors will be identified offering a means of management."

Sheldon says the most important factors in the management of sleep terrors is protecting the child and remaining calm.

"Parents will see the event as horrifying," says Sheldon. "It may be horrifying to the parent, but the children are fine. Parents can help their children by ensuring they do not harm themselves when they walk or run around the house by using bells on doorknobs and safety gates. It is important that the parent remain calm and does not attempt to wake the child which could only make the episode worse and may cause it to last longer."

Sleep terrors can often scare parents. However, knowing what they are, what to do and not do can help parents not only understand the sleep terrors themselves but also deal with the occurrence properly.

"Education and understanding are the key," says Sheldon. "Ask questions; ask lots of questions. Once you know what your dealing with it can make the situation much easier on both you and the child."