As you ask this under Medications, I choose to interpet the question to mean what meds act that way? This pattern occurs quite frequently with hypotensives; meds that reduce blood pressure, including alpha and beta blockers as well as others. You may want to check your blood pressure a few times a day and see what's happening, as "blood pressure cocktails" can easily cause postural hypotension - a sudden low blood pressure that appears if you stand or sit, but typically resolves if you lie down. This is especially important, if you drive a car. If you're taking heart meds and/or seeing a cardiologist, this would be a good discussion to have. You may also see a similar effect on medium to high doses of pain meds, where one falls asleep episodically and for short intervals while sitting. Note that this is not the same as the "drowsiness" the labels warn about, as this persists for the duration of the med's time in system. Try as I might I can't find the etiology on this one.
The most common reason is that you do not get enough sleep. Adults usually need 7-8 hours of sleep per night and teens need more. Most do not get that much.
Other reasons might include sedating medications or a sleep disorder such as restless legs syndrome, obstructive sleep apnea and narcolepsy.
You should first ensure adequate sleep. If you are still having problems despite getting 8 hours of sleep per night then you should see your doctor. Most of these disorders are treatable and can cause health problems other than just being sleepy.
Without knowing the details of your question, I am assuming that your sleep is not the regular "going to bed at night" sleep, but rather sleep that is occurring when you don't want to be asleep, and is bothersome.
Of course age, health status, and many,many other factors would be needed to properly answer this question, but a broad answer will be used.
The average adult human needs 8 hours of continuous sleep in order to keep their body healthy.
When sleep is interrupted, from illness or stress/anxiety, etc, then often the person will become sleepy during the day, and the urge to fall asleep will be strong.
IF the sleep is happening without the urge, and the person is just falling asleep and not remembering what happened before they fell asleep, this could be a sign of a condition called "narcolepsy", which causes a person to suddenly fall into a state of sleep without warning.
If this is occurring, than a full examination by a doctor is a good idea!
Most people, however, simply struggle with when to sleep, and how much.
Perhaps you are falling asleep because you are :
not getting enough sleep at night, or not getting the right TYPE of sleep.
(are you falling asleep in front of the TV, or are you going to bed?- are you waking up frequently during the night?)
Diet and exercise play a huge role in the type of sleep we get- and thus can affect the need to constantly sleep. If you are not getting the vegetables, fruits, and nutrients needed for a healthy, functioning body- then your body will not have the energy it needs to continue to function all day without sleeping.
Your health status plays a big role- for example those people with liver failure will often fall into a semi-conscious state called "hepatic encelphalopathy", where they are not quite asleep, but not awake either. This happens because the liver failure does not allow the liver to filter out toxins that naturally build up in the body- and the toxins end up going to their brain and amking them safe.
A check up at the doctor is a good idea if your sleeping habits are poor and interfering with your work, school, or everyday life- as there are too many issues and disorders that "falling asleep too much" are symptoms of!!
then your asleep but your sitting up arnt you glad you learned something new
normally it happens when you have stood up for a long time but if not maybe it's just dehidration!
Why do I fall asleep when I sit down?
to keep from falling asleep
I think you did not have enough sleep, or you get bored very easily. Try to test out these things to find out why you keep falling asleep
because they are poops
It is called narcolepsy.
because you sleep for 12 hours and keep on farting
The most common reason to fall asleep while driving is that you are sleep deprived or on medication which causes you to fall asleep. You should not drive if you fall asleep while doing so, as it is highly dangerous for you as well as other drivers. If you are receiving enough sleep and are not on any medication, you should discuss your problem with your doctor. You may have a very serious medical condition such as narcolepsy.
That's to keep the reader from falling asleep.
Sounds like a problem with circulation. You need to move around more to keep your blood moving. If you sit too long or sit on your feet, they "fall asleep." Move them more often, get up, walk around, and your feet will not fall asleep so much.
drink coffee/soda, walk around, listen to music, talk to someone
If it's early, drink some soda (something with caffeine) - keep your mind awake. Have a lot of light in the room (I have a hard time sleep-reading when it's bright). Or read standing up!
Central nervous system stimulants are used to keep patients who suffer from narcolepsy from falling asleep. Narcolepsy is a disorder that causes people to fall asleep during daytime hours.