Every night, nearly every person undergoes a remarkable change: we leave waking consciousness and for hours traverse a landscape of dreams and deep sleep. When we wake, we typically remember little or nothing about the hours that have just passed. Except in rare instances, we never contemplate and appreciate that we are sleeping while we are asleep. Thus, although everyone sleeps, most people would be hard-pressed to precisely define sleep. All organisms exhibit daily patterns of rest and activity that resemble the daily sleep and wakefulness patterns seen in humans. From observing changes in behavior and responsiveness, scientists have noted the following characteristics that accompany and in many ways define sleep:
- Sleep is a period of reduced activity.
- Sleep is associated with a typical posture, such as lying down with eyes closed in humans.
- Sleep results in a decreased responsiveness to external stimuli.
- Sleep is a state that is relatively easy to reverse (this distinguishes sleep from other states of reduced consciousness, such as hibernation and coma).
From observations of behavioral changes that accompany sleep and simultaneous physiological changes, scientists now define sleep in humans based on brain wave activity patterns and other physiological changes.
Sleep is important for a number of reasons. It restores our energy, fights off illness and fatigue by strengthening our immune system, helps us think more clearly and creatively, strengthens memory and produces a more positive mood and better performance throughout the day. Sleep isn't just a passive activity and something to fill the time when we are inactive, but rather it is an active and dynamic process vital for normal motor and cognitive function.
Most adults need somewhere between 6-10 hours of sleep per night. Different people need different amount of sleep to feel rested. If you are frequently tired or irritable during the day and find yourself sleeping more than an extra 2 hours per night on weekends, then you are probably not getting enough sleep during the week. Try for 7-8 hours and see how you feel.
Lack of sleep is associated with both physical and emotional health risks. These include:
- More illness, such as colds and flu, due to a lowered immune system
- Feeling more stressed out
- Increased weight gain and obesity
- Lower GPA and decreased academic performance
- Increased mental health issues, such as depression and anxiety
- Increased automobile accidents due to fatigue caused by "drowsy driving"
- Decreased performance in athletics and other activities that require coordination
Lack of sleep can cause many health issues, including death, and people are often not aware that they are at risk. Since sleep deprivation can impact the immune system function, our ability to fight off infections becomes more difficult and we are more prone to getting upper respiratory infections, such as cold and flu, and often feel "run down." That's because we are! Heart and lung function is adversely affected by lack of sleep and is associated with worsening chronic lung and heart disease and high blood pressure.
Lack of sleep has been linked to obesity. With sleep deprivation, there is an increase in the hormone, ghrelin, which is associated with hunger for high calorie foods. There is a decrease in the hormone leptin which reduces appetite. This leads to weight gain in many people. Lack of sleep impacts brain function, attention span, mood and reaction times. Excessive sleepiness is a leading cause of car and truck accidents, and research has demonstrated that many industrial accidents and disasters, such as nuclear power accidents, major oil spills and space shuttle disasters have been attributed to sleep deprived workers.
College students are often at risk for having mental health issues such as depression and anxiety, and researchers believe that lack of sleep is a factor. An assessment of your sleep by a mental health professional may be best if you exhibit one or more of the following symptoms.
Sleep and Depression
- Insomnia (often sleeping 6 hours or less a night)
- Too much sleep (often sleeping 10 hours or more a night or "escape sleeping")
- Regularly feeling fatigue, constantly wishing you were sleeping or napping
- Engaging in day to day responsibilities feels highly tiring or burdening
Sleep and Stress/Anxiety
- Racing thoughts (very high paced) that prohibit settling into sleep
- Recurrent and persistent thinking about 1-2 topics that prohibit settling into sleep
- Repetitive behaviors that needed to manage anxiety that inhibits falling asleep
- Pattern of stressful and anxiety-provoking thoughts that wake you up during sleep
- Experiencing shortness of breath when attempting to fall or stay sleep (that can't be explained by a medical condition)
Sleep and Relationships
- Trouble enjoying activities within your relationships that are typically fun
- Difficulty regularly listening to what your partner has to say
- Pattern of being quick to get irritated or angry with your partner (increased fighting)
- Regular quality of communication is reduced or more difficult
According to a health survey administered at UofL every other year, 1 in 3 UofL students indicate that lack of sleep has impacted their academic performance in a negative way: lower grades, missed a paper or project deadline, or had to withdraw from class.
The very qualities you need to maximize in order to do well on tests, such as recall, concentration, and alertness, are decreased when you are sleep deprived. Research has shown that students who get 6 or fewer hours of sleep have a lower GPA than those who get 8 or more.
During sleep, the brain organizes, sorts, and stores what we have learned and experienced that day, making it easier to recall at a later time.
Sleep also helps you weed out irrelevant information and helps you make connections between your memory and information you learned that day, even if you have not made those connections while awake.
If you study a little every day, you can use this natural process of sleep to gain a better understanding of the material and to retain the information more efficiently.
If you don't understand something you have read or you can't solve a problem, look it over and then sleep on it.
To sum up, to study better, more efficiently, and to increase the likelihood of learning and retaining information, get at least 6-8 hours of sleep before your exam. Go for 8!
Individuals regularly getting high quality sleep often have a sleep ritual. A sleep ritual is a routine that helps the mind and body wind down at the end of the day in preparation for a good night's sleep. In evaluating your sleep, does your sleep ritual include the following?
- Maintain a regular bed and wake time schedule including weekends. Sleeping more than 1-2 hours more on the weekend can wreak havoc on your circadian rhythms, so a regular wake schedule is important.
- Establish a regular, relaxing bedtime routine such as soaking in a hot bath or hot tub and then reading a book or listening to soothing music.
- Create a sleep-conducive environment that is dark, quiet, comfortable, and cool.
- Sleep on a comfortable mattress and pillows.
- Use your bedroom only for sleep and sex.
- Finish eating at least 2-3 hours before your regular bedtime.
- Exercise regularly. It is best to complete your workout at least 2 hours before bedtime, as exercising before you sleep can leave your body too energized to relax.
- Avoid caffeine (e.g. coffee, tea, soft drinks, energy drinks, chocolate) 3-4 hours before bedtime. It can keep you awake.
- Avoid nicotine (e.g. cigarettes, tobacco products). Used close to bedtime, it can lead to poor sleep.
- Avoid alcohol close to bedtime.
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Alcohol can make you feel tired because it is a depressant and has sedative qualities, but drinking alcohol can interrupt sleep and interfere with the quality of your sleep. It can also magnify the effects of sleep deprivation.
Approximately 30-50% of college students nap, but the effect is that nappers sleep less than non-nappers. If you do nap, nap early in the day and keep it to about 20-30 minutes.
Flash Napping Benefits
Setting aside even 20-40 minutes a day for napping is helpful for reducing irritability, anxiety, depression, reaction time, and improving critical thinking and cognitive abilities, especially if a student does not or cannot get a decent 6-9 hours of sleep every night. Utilizing good flash napping skills and avoiding crash napping (such as sleeping for up to 2 hours instead) will help you wake up feeling refreshed and energized, ready for work, another class, or anything.
Keeping a schedule is important. Put a routine nap time in your calendar. Other tips for reaping the benefits of flash napping include:
- Reduce the effects of visual and auditory stimuli by covering your eyes and ears. Consider using a sleep mask and ear plugs.
- Turn off phones, laptops, and other electronic devices, and put them out of reach such as in your backpack or on the other side of the room. The light emitted from the screens suggests to your brain that it’s time to wake up.
- Set an alarm with a pleasant sound for wake-up time. Nothing is more startling than a sudden, obnoxious BEEP BEEP BEEP to wake you up.
Avoid caffeine, alcohol, and high-fat foods prior.
Most of us have difficulty falling asleep or staying asleep at some point in our lives. Sometimes these problems are temporary and can be due to stress. In other cases, the problem persists for weeks or even months. If you are unable to fall asleep for more than 30 minutes after going to bed, 3 or more nights per week for 4 weeks, then you may have what is known as primary insomnia. This may be due to psychological and/or physiological causes, and if it persists for more than a month, you should see your clinician.
Other sleep disorders:
Narcolepsy is an inherited condition of excessive sleepiness that causes temporary loss of muscle control and/or uncontrollable sleep attacks". There is no cure for narcolepsy, although it can be controlled through drug treatment.
Obstructive sleep apnea is a condition in which the soft tissue of the upper airway repeatedly collapses during sleep and cuts off breathing for a short time, and then the airway opens abruptly and noisily. The constant interruptions of sleep cause excessive sleepiness during the day, but sleep apnea may go unnoticed unless someone sleeps in the same room and hears interruptions. Obesity increases the risk of this disorder.
Restless legs is a condition in which the legs jerk uncontrollably during sleep, disturbing sleep and causing daytime sleepiness.
Consider seeing your clinician if you:
- Have trouble getting to sleep or wake up frequently during the night for a period of several weeks
- Fall asleep at inappropriate times even after a night of adequate sleep
- Have nightmares or night terrors (the experience of awakening in a terrified state without recollection of a dream) that interrupt your sleep
- Have been told by someone that you stop breathing during sleep, especially if you have morning headaches or fall asleep easily during the day
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