7 month old always tired

He’ll take a nap and wake up then he’s already rubbing his eyes again to go back asleep. I feel like he sleeps a LOT and I’m not sure whether I should be concerned or not. Like he can’t really stay awake for more than an hour if that. And it also seems like he’s been crying a LOT more than usual. He just got his first tooth last week but it looks like it’s already poked through the gums and just needs to come fully out. I don’t know if that might have anything to do with it? I honestly can’t vouch for his night sleep because I am not the one that gets up with him but he definitely doesn’t sleep all night. Is this normal or could something else be going on?