Swollen, painful upper lid. whats causing it?

I have severe allergies, and having a cold doesn't help. But recently last night, my eyes started watering profusely, so I dabbed away the fluid below my eye with a tissue, making sure not to touch my eyeball, or my lids. But when I woke up this morning, my tear-duct on my right eyes lid was swollen. It hurts to blink, or to touch it. I do not wear makeup, nor contacts. I haven't used any face wash or topical face products within 24 hours, or even touched my eyes. I'm not sure what could be causing it. If you know what is, it would be greatly appreciated if you told me how to stop the swelling. thanks!:)