Sleep is essential for a person's health and wellbeing. Yet millions of people do not get enough sleep and many suffer from lack of sleep.  If a sleep-deprived person doesn't sleep after the initial signs, the person may then start to experience apathy, slowed speech and flattened emotional responses, impaired memory and an inability to be novel or multitask. Everyone's individual sleep needs vary. In general, most healthy adults are built for 16 hours of wakefulness and need an average of eight hours of sleep a night. However, some individuals are able to function without sleepiness or drowsiness after as little as six hours of sleep. Others can't perform at their peak unless they've slept ten hours. And, contrary to common myth, the need for sleep doesn't decline with age but the ability to sleep for six to eight hours at one time may be reduced .

Stress is the number one cause of short-term sleeping difficulties, according to sleep experts. Common triggers include school- or job-related pressures, a family or marriage problem and a serious illness or death in the family. Usually the sleep problem disappears when the stressful situation passes. However, if short-term sleep problems such as insomnia aren't managed properly from the beginning, they can persist long after the original stress has passed.

Drinking alcohol or beverages containing caffeine in the afternoon or evening, exercising close to bedtime, following an irregular morning and nighttime schedule, and working or doing other mentally intense activities right before or after getting into bed can disrupt sleep.

Traveling also disrupts sleep, especially jet lag and traveling across several time zones .Environmental factors such as a room that's too hot or cold, too noisy or too brightly lit can be a barrier to sound sleep. And interruptions from children or other family members can also disrupt sleep. Other influences to pay attention to are the comfort and size of your bed and the habits of your sleep partner. If you have to lie beside someone who has different sleep preferences, snores, can't fall or stay asleep, or has other sleep difficulties, it often becomes your problem too! Having a 24/7 lifestyle can also interrupt regular sleep patterns.

A number of physical problems can interfere with your ability to fall or stay asleep. For example, arthritis and other conditions that cause pain, backache, or discomfort can make it difficult to sleep well. For women, pregnancy and hormonal shifts including those that cause premenstrual syndrome (PMS) or menopause and its accompanying hot flashes can also intrude on sleep.

Finally, certain medications such as decongestants, steroids and some medicines for high blood pressure, asthma, or depression can cause sleeping difficulties as a side effect.

In  young teenagers whose preschool sleep habits were poor were more than twice as likely to use drugs, tobacco or alcohol.  The study found a significant connection between sleep problems in children and later drug use, even when other issues such as depression, aggression, attention problems and parental alcoholism were taken into account. Nightmares are dreams with vivid and disturbing content. They are common in children.

How to get a good night sleep

• Keep a regular sleep/wake schedule
• Don't drink or eat caffeine four to six hours before bed and minimize daytime use
• Don't smoke, especially near bedtime or if you awake in the night
• Avoid alcohol and heavy meals before sleep
• Get regular exercise
• Minimize noise, light and excessive hot and cold temperatures where you sleep
• Develop a regular bed time and go to bed at the same time each night
• Try and wake up without an alarm clock
• Attempt to go to bed earlier every night for certain period; this will ensure that you're getting enough sleep