Why can't I stay awake in class?

Hey Alice,

Lately, I've come to realize that I have a very powerful tendency to fall asleep in class. It seems that I can't stay awake in any lecture style class where I have to listen to the professor and take down notes — where there is minimal engagement on my part. I've pretty much fallen asleep in all of my lecture classes, during one part or another for the whole semester. I think I'm getting regular sleep — six hours at a minimum. I don't like to drink coffee or anything.

Dear Reader, 

Even if your professor has the charisma of a potted plant, your regularly scheduled naps might mean that you aren’t getting enough zzz's in general, or that you’ve consumed something that makes you sleepy such as a particular food or medication.  People don’t usually feel tired when they’re active, or in your case, when they’re engaged in a discussion-based seminar with fewer opportunities to doze off. As you noted, however, you’re minimally engaged during your lecture which may lend itself to a more relaxed environment with low engagement or limited motivating stimuli. This can cause boredom, which can contribute to drowsiness. That said, let’s review other reasons you may be falling asleep in the classroom. 

You mentioned that you sleep at least six hours every night. Regular, consistent sleep is great, but you might not be getting enough sleep overall. On average, adults between the ages of 18 to 65 years old need around seven to nine hours of sleep. Of course, this amount may vary from person to person, depending on factors such as brain function, physical activity levels, circadian rhythms, diet, and genetics. For example, people who are naturally short sleepers tend to sleep for less than six hours per night and continue to function well. This is possibly due to a gene mutation. Note that natural, short sleeping is different from insomnia. The former isn’t a disorder; however, the latter is a sleep disorder characterized by difficulty falling asleep or maintaining sleep. Other reasons for compromised sleep can include an impairment to the suprachiasmatic nucleus, which is a structure in the brain that regulates the sleep-wake cycle. Similarly, those with disrupted circadian rhythms might find themselves struggling to regulate the body’s natural process of maintaining the sleep-wake pattern. 

The quality of sleep matters as well, and it can impact your alertness during the day. Your sleeping environment may be particularly impactful on your sleep quality. A quiet, dark room, for example, will likely contribute to a more restful slumber, compared to a noisy, bright room. The National Sleep Foundation also recommends limited use of electronic devices before sleep. Research studies show that screen time before bed can disrupt your quality of sleep. What you eat or drink before sleep can also impact your sleep. Though you aren’t a coffee drinker, are you eating or drinking other things before class? The timing or composition of meals can also affect your level of fatigue. Eating a big meal or food high in fat, carbohydrates, or caloric content might lead to drowsiness. High levels of melatonin or tryptophan can also trigger sleepiness. There are also several medications that have sedative effects. These might include antihistamines, antidepressants, muscle relaxants, or pain medicines, to name a few. Combinations of medications can also interact in the body to make you sleepy. 

While it may be hard to pinpoint whether your class time naps are due to insufficient sleep, food, medication, or the classroom itself, you may choose to experiment with some of these strategies to combat your drowsiness: 

  • Drink cold water: Water can keep you alert, and the cold temperature might “shock” your senses into waking up. 
  • Engage in the class: Ask questions and sit closer to the front. 
  • Take a break and move your body: This may be more difficult depending on the class, but being able to move your muscles can keep you alert. Exercising before class will also naturally increase your energy and alertness. 
  • Maintain a sleep schedule: Aim for at least seven hours of sleep and try to sleep and wake up at the same time every day. 
  • Limit caffeine intake: Although you don’t drink coffee, be mindful of other products with caffeine and limit the intake of caffeine after 2 p.m., or within eight hours of bedtime. 
  • Be mindful of screen time: Blue light emitted by screens can interrupt the production of melatonin at night. 
  • Instead of watching your favorite show before bed, consider reading a book or exploring another relaxing pastime

Another consideration for why you may be more inclined to drift off during class could be attributed to your learning style. Perhaps passive learning isn’t your style and more active, participation-oriented classes could perk you up—this could be something to consider the next time you register for courses. If you’re stuck with large lectures in larger halls, choose a seat in the front, close to the blackboard, projector, screen, and the lecturer, to help you pay better attention and be more engaged in the material being taught. 

You may also consider discussing your sleep experience with a health care provider. It’s helpful to rule out any underlying health conditions making you tired. For related information on sleep, consider reviewing the Sleep category in the Go Ask Alice! archives, which includes more information such as the connection between sleep or physical activity. 

Last updated Aug 11, 2023
Originally published Apr 15, 2004