I have a daughter who is turning 5 months old this week. My question is that she doesn't sleep very much. When she was about 2 months old she would sleep from 11 PM to 8 AM. Now, she doesn't fall asleep until 3 AM and wakes up every hour crying. If I pick her up and walk around with her, she usually will fall asleep again. Do you have any advice on how we can get our daughter to sleep?
The sleep pattern you describe for your 5-month-old is one I hear quite often, and one that I find most often occurs when babies become dependant on falling asleep with some sort of sleep "aid"—most commonly in the form of a bedtime bottle, nursing, and/or being rocked or held to sleep. While these sorts of well intentioned, loving activities may not cause any sleep disturbances in the first few months, sometime around 3 to 5 months of age they often end up posing just the kind of problem you are now faced with.
Fortunately, the solution is often easier than sleep-deprived parents fear. By 5 months, we know that normal, healthy babies should be able to sleep through the night—especially if they've already proven that ability (as your daughter did beginning at 2 months!). It's therefore likely to be most effective for you to take a look at how you are putting your daughter to sleep at the beginning of the night, with the goal of making sure that she has learned to fall asleep independently. The reason this is so useful for babies over 2 or 3 months of age is because all babies (and adults) cycle through light sleep several times a night. When babies have been rocked, fed, or otherwise assisted in falling asleep, they run the risk of needing those same interventions (such as you walking around with your daughter) to lull them back to sleep each time they go through a light sleep cycle or awaken during the night.
The best way I've found to institute a healthy yet soothing bedtime routine that allows babies to learn to fall asleep on their own is to offer the last breast or bottle feeding of the day, then bathe your baby (either as a matter of routine, or as a new, useful way to insure that your baby hasn't taken the feeding as her cue to fall asleep). Then put on her pajamas, read a few books, and commit to making sure your baby is laid down safely on her back in her crib while still awake. While it may take babies a couple of nights to adjust to falling asleep from a more awake state, they will quickly be able to apply this important life skill throughout the night—allowing both them and you to get a much more restful night's sleep.