If it takes a while to fall asleep at night, you're in good company. Many people struggle to slip into the Land of Nod for various reasons. It's normal to fall asleep 10 to 20 minutes once you climb into bed (this is called sleep latency). If it takes more or less time, your body may be trying to tell you something.
If it takes an hour or longer to nod off, you may be sleeping too much or grappling with insomnia; this can happen if you have trouble relaxing and turning off your thoughts at night. It can also happen if your body isn't ready for sleep because you had too much caffeine or your internal clock is out of whack for another reason (such as jetlag). The first step is to try to improve your sleep hygiene. If that doesn't help, talk to your doctor about what you can do to fall asleep more easily.
If you fall asleep as soon as your head hits the pillow: This may be a sign that you're not sleeping enough. In that case, you're on notice that you should prioritize getting more snooze time. If you don't, skimping on sleep is bound to catch up to you eventually, probably not in a good way.