It's not unusual for the typical college student to stay up late on a regular basis. Exams, papers, extracurricular activities and weekend parties make it nearly impossible to go to bed early.

Like Americans overall, the average college student is not getting enough sleep. According to Dr. Mary Buchwalder, medical director of the UD Student Health Center, young adults require seven to nine hours of sleep a night.

'Students require a lot more sleep than they are getting,' Buchwalder said. 'On average we have students getting only five to six hours a night.'

Sleep is necessary to maintain a person's circadian rhythms, restore body functions and strengthen the immune system. It also rests the mind and prepares a person for the next day's challenges.

'Sometimes the stress of homework causes us to stay up too late,' said Michela Buccini, junior public relation major. 'Stress can really take a toll on a person after a while.'

College students may believe they are being more productive when they sleep less, but in reality it is causing harm to their bodies. The National Sleep Foundation points out that receiving less than six hours of sleep a night is associated with 1.7 times greater risk of disease, according to http://www.sleepfoundation.org. The chance of decreased academic performance, driving accidents, colds and flu and mental illnesses are all increased.

'When students come and visit the Health Center, it is primarily for illness reasons such as a cold or flu,' Buchwalder said. 'We then ask them about their sleep habits, and we are able to see a direct connection.'

The National Sleep Foundation also claims a lack of sleep is linked to depression. Among college students, depression is two times more common than in the general population, and it affects about 20 percent of students. Symptoms may include a lack of energy, loss of interest in activities, moodiness, weight change and more or less sleep.

'The Health Center and Counseling Center work with students who have sleep problems caused by anxiety or depression,' Buchwalder said. 'These diseases cause disrupted sleep patterns, but mostly illness from not enough sleep is just caused by bad habits.'

There are several tips students can use to get better sleep. Maintaining regular rise and bed times will help regulate sleep. According to Buchwalder, a 1 a.m. bedtime is fine as long as it is maintained.

'Try a routine before bed,' Buchwalder said. 'Relax, avoid caffeine late and practice good sleep hygiene.'

Other tips include not eating food two hours before bedtime, taking hot baths before sleep, turning down the thermostat, avoiding electric blankets and drinking warm milk.

Sleeping pills should be avoided. Diet pills and nicotine will also disrupt sleep.

Many college students rely on naps to help them stay up late. According to the National Sleep Foundation, 30 to 50 percent of students nap. Taking a nap is not recommended because it reduces the amount of time a person sleeps at night. If needed, it is recommended to nap early in the day and only for a short period of time, between 20 and 30 minutes.

'Try to avoid napping as much as possible,' Buchwalder said. 'It will only affect your quality of sleep in the long run.'

'I hate taking naps because it messes up my sleeping patterns,' Buccini said. 'But I feel a nap is necessary for me to make it through the day and feel refreshed.'