Slideshow: Top Reasons Your Child Can't Sleep, Including You

Few babies sleep through the night right away. For the first two months, newborns sleep off and on at random times for 12 to 18 hours a day. Most babies sleep through the night by the time they're about 9 months old. Even then, "night" means just five to six hours in a row.

Rock a baby to sleep every night, and they can't learn to fall asleep on their own. Instead they cries to get what helps them -- you. Put them to bed when they're sleepy, but not sound asleep. They'll become a "self-soother" who learns to fall asleep on their own, even if they wake up in the middle of the night.

Toddlers and preschoolers need 11 to 14 hours of sleep every 24 hours, including nighttime and naps. Routine is key, so set regular times for bed, waking up, napping, meals, and play.

It's normal for your child to go through this phase. Try not to encourage it with lots of talking, singing, rocking, or extra feedings. At around 6 months, you can help a baby to go back to sleep on their own. As long as they don't seem sick, speak softly and rub their back. Comfort them, but don't make it too rewarding by picking them up or feeding them. A nightlight may comfort toddlers who are afraid of the dark.

Doing the same things each night before bed helps your child know it's time to sleep. Create a bedtime routine to wind down and relax. For instance, each night your child gets a bath, listens to you read them a story, has a snack, and then it's lights out. Do the same routine every night and always end in your child's room. It's best to start a routine early, by 4 months.

Some kids delay bedtime. They make up reasons to stay up or ask for more stories, a drink, or a trip to the potty. Stick to the routine. Go into your child's room to respond. Be kind and firm. Make your visits shorter each time. Let your child know it's truly time for sleep.

If they don't nap enough during the day, young kids may have trouble falling asleep at night. Most babies need two or three naps a day. Toddlers need at least one nap. Most kids still take an after-lunch nap until age 5. If your child is cranky and sleepy, let them nap, as long as it's not too close to bedtime.

It's rare, but some children can't sleep due to obstructive sleep apnea -- when the airways are blocked, often by enlarged tonsils and nasal tissues called adenoids. Kids with sleep apnea usually snore loudly, have labored breathing, and restless sleep. It affects about 1 in 100 kids and is most common from ages 3 to 7, when tonsils and adenoids are at their biggest. Treatment includes surgery or having the child wear a nose mask at night.

About 1 in 10 kids snore. They can snore for many reasons, including sleep apnea, seasonal allergies, stuffiness from a cold, or a deviated septum. If their sleep is OK, your pediatrician probably won't treat snoring. But see your pediatrician if your child isn't sleeping well because of snoring or breathing problems.

Kids occasionally have bad dreams. That's normal, and most bad dreams are harmless. Soothe your child after bad dreams. Make sure they get enough sleep and has a soothing bedtime routine. If bad dreams won't stop, mention it to your pediatrician.

Some children sleepwalk. When they're not fully awake they may walk, talk, sit up in bed, or do other things. Their eyes may be open, but they're not aware. Most kids outgrow this by their teens. Don't wake a child who sleepwalks. You may scare them. Gently guide them back to bed. Keep the area they may roam in safe: Lock doors and put up safety gates near steps.

Some health problems can keep kids from sleeping. Stuffy noses from allergies, colds, and asthma can make it hard to breathe. In babies, colic, acid reflux, earaches, or teething pain can also hamper sleep. Your pediatrician may be able to help. 

Some cold and allergy medicines or ADHD drugs can affect a child's sleep. If drugs seem to be keeping your child up, talk to your pediatrician to see if changing the drug, dose, or timing might help. Never make those changes on your own. 

When a child becomes a teen, their sleep cycle changes. They become more alert in the evening and sleepier in the morning. Work with those changes. Let your teen do homework at night and sleep later if they can. Teens still need at least 8.5 hours of sleep.

Sometimes having a special object close by can help a young child fall asleep. Blankies or stuffed animals are among the top comfort objects. Pacifiers may please a baby's need to suck, even if they're breastfeeding. A white noise machine soothes their ears and hushes sounds.   

To create the right space for sleep, keep your child's room dark at night. (A small nightlight is OK.) Dress your child in something lightweight and comfy. Keep the room quiet. Shut the door if your child can hear a TV or people elsewhere in your home.

Is your child nodding off at school? Do they have trouble falling asleep within 30 minutes of going to bed, or getting up in time to start their day? Check that they're getting enough sleep. Kids ages 5 to 10 years need at least 10 hours of sleep a night.

Phones, computers, video games, and TVs can be irresistible. Keep them out of your child's bedroom. Power down before bedtime. Even big kids need a relaxing routine to wind down for bed.

Stress can affect kids' sleep. Help them relax with deep breathing, a warm bath, and a calm bedtime routine. You can also start teaching them good ways to manage stress during the day, so it doesn't affect their sleep.