I am in my second year at college and I have found myself falling into an unhealthy sleeping pattern. I sleep mostly at night (I don't nap too much) and don't go to bed too late (usually between 12 to 2 am). But, unless I have some huge incentive to get up in the morning (class, etc.), I can sleep extremely late (1 to 2 pm). This makes me end up feeling even sleepier throughout the rest of the day. How can I keep myself from oversleeping?
Rest assured that while your sleeping pattern isn't necessarily abnormal or unhealthy, it may keep you from achieving your maximum potential in school (and other life areas). A typical college student between the ages of 18 and 25 needs between seven to nine hours of sleep a night. Keep in mind that these aren't absolute values and fluctuations on either end are common and normal.
If the amount of time you're sleeping actually causes you to walk around rubbing your eyes and feeling more tired, it might be a good idea to try and cut back on your z's. It's interesting that you mentioned being able to get up in the mornings when you need to. To get yourself out of bed before it gets too late, you can try scheduling classes, work, exercise, library time, or even breakfast or brunch plans with friends in the mornings. You could also start small by putting your alarm clock farther away from your bed so that you have to get out of bed to turn it off. Keeping it on the highest volume, having multiple alarm clocks in your room, and even having your friends call you or stop by in the morning to wake you up may also help you get going in the morning. Other strategies may include shifting your sleeping times (e.g., going to bed a bit earlier and waking earlier) or seeing a sleep specialist to determine if something else is happening.
Lack of sleep during certain days of the week may cause your body to try and get more sleep whenever it gets a chance. In extreme cases, a person may suffer from hypersomnia, which is marked by excessive daytime sleepiness and/or long periods of sleep at night. These individuals also nap during the day and are more likely to fall asleep during meals, in mid-conversation, or during work or school. Even (frequent) naps do little to relieve related symptoms of disorientation, anxiety, restlessness, or loss of appetite.
Because you mention that you don't nap much during the day, this condition most likely doesn't apply to you. If, however, you do begin to experience any of these symptoms and you think it may be related to your sleeping patterns, you may want to visit your health care provider. S/he can examine you to see what's behind your sleepiness and provide or prescribe a course of treatment to address it. Also, make sure you're sleeping well at night. One study suggests that for college students, sleep quality may be more beneficial than sleep quantity. It could be that you're sleeping so much to compensate for lack of good sleep.
Regardless of the strategies you choose, finding the right balance of sleep quantity and quality will change a few times during the average lifespan. Be prepared to try new things and find your own sleep system that allows for success.