Can hamsters have allergies? Or is he just sick?

Normally Crash, my teddy bear hamster of 7-8 weeks, is an energetic ball of fluff. He'll run in his wheel for 1hr+ non-stop. Today, the most he's done was drink some water and go back to sleep. He's been doing a lot of sneezing(he just had a sneezing fit) and I'm worried about him. He's drinking right now. Also, I've held him a few times today like I normally do and all he's done is sleep in my hands. Normally the little worm tries to squirm out of my hands and escape. His nose is kind of wet(like it should be) but I'm concerned as he doesn't act like this much. What is wrong with him, if anything, or is he just in a lazy day today?

hamsters are nocturnal! this means they sleep during the day and are awake during the night. So this might be part of the problem.

If he is sneezing, make sure you are using Aspen wood shavings for bedding. Your hamster may be allergic to other kinds of bedding. Mine kept losing her fur until i changed to aspen wood shavings, then she was fine and her fur grew back.

Check his eyes, if they are not bright and clear, that could be a sign of illness. Check the tail. If it is wet, he might have wet tail. If he has diarrhea, he probably has wet tail. They sell medicine for wet tail, but he needs to take it right away if he does have it. The medicine might come as a liquid in a bottle that should be hand fed to him, or tablets that should be dissolved into his drinking water.

Had two hamsters who lived long, full lives =)