Could be lots of things, really. Allergies, cold, etc. My mom told me about this item that's supposed to work great for clearing sinuses. I've never tried it, but it's worth a look. It's called a neti pot. Actually it looks kinda icky to me, but some people swear by it. Found demonstrations of it on YouTube. This one's the best I've seen... http://www.youtube.com/watch?v=aQm7YpxgOnA

Currently I'm with a stuffed nose that is quite un-comfortable, it prevents me from sleeping and causes me giant stress, the steam trick will work for 1-2 hours, 10-15 min of inhaling steam will do it, Claritin nose spray is very bad, as is all of the nose sprays, one of the side affects is increased nasal discharge, now your back at the start, someother tricks are boiling water and after its cooled down enough that you can drink it (Warm not cold) kinda of drown yourself, snort it up and you will caugh and sneeze, my last couple tricks are some what odd, but they work, get a tissue roll it up into a spear shape with a big end (buldge at the end) and stick it in your nose, (the nostril that is stuffed) and continue to sleep, this works couse your body doesn't know that its stuffed, ^_^ my last trick requires a bit of work go to a health food store and get elderberries they raise your imunesystem (but i'll explain what you do) first get salt and water, mix them together, boil the water (saturateing the salt) and put some drops of that in your nose, now, get a bowl and boiling water, now i use just normal steam but peppermint tea would also help. your almost done afert doing that drink lots of O.J (Orange Juice) after you feel full eat the elderberries (make a smoothie with oranges elderberries and pomagranete if you have it) Your nose should be all cleared up, and your imunesystem is now higher than what it was previously, so just relax the whole day, eat chiken noodle soup, it calms your nurves and makes mucous (can't spell ^^) thinner