He's Afraid of Monsters
You know how badly you sleep when you've got a lot of worries on your mind. The same goes for your toddler, though he's panicking about monsters, not the mortgage. "This is the stage when your child's imagination really takes off," says Spivack. "Even if he wasn't afraid of the dark before, he may start 'seeing' ghosts and other eerie creatures."
Rest easier by... respecting your child's fears. Let him know you understand how scared he feels, but beware of making his anxiety worse. Using "monster spray," for example, actually suggests that creepy creatures could be hanging out in his room, says Dr. Kuhn. Instead, reassure him that you're always nearby and that monsters don't exist.
Look for ways to convince your toddler that his room is a safe place. Play in his bedroom more often so he associates it with good times, or "camp out" with him there for a night. You could also appoint one of your child's stuffed animals the "watch pet," says Carol Ash, medical director of Sleep for Life in Hillsborough, New Jersey. "I gave my son a big bear that he could prop up on his bed all night to keep an eye on him."