If a baby’s not sleeping (like my daughter over the past couple of nights), the first thing to do is to be systematic in ruling out serious problems by making sure that the baby is comfortable, not sick, and otherwise has a good sleeping environment.
So, this means first making sure that the baby is comfortable. This requires mentally answering a laundry-list of questions like the following (which is by no means exhaustive or 100% complete): Does the baby have a dirty diaper? Is the baby teething, or in pain for some other reason? Is the temperature and humidity in the room set right? Is the baby’s sleepwear appropriate for the season? Etc, etc…
Also, you want to make sure the baby isn’t sick. Start by checking his or her temperature to rule out a fever. Is the baby’s nose and throat clear of mucus? A sick baby will almost certainly have trouble sleeping.
When you have a child that is usually a good sleeper, it is easy to overlook some of these important questions. Take my daughter, for example. Last night, she had trouble sleeping for the 2nd night in a row. It turns out that she was hatching some sort of an illness, and had a low-grade fever. In this case, because fever was the culprit, a dropper full of Tylenol and her sleep problems were soon solved. However, all the white noise and other baby sleep techniques in the world weren’t going to work, until I helped make her comfortable.
As a parent, when you have a baby who isn’t sleeping, it’s important to remember to make sure there aren’t serious problems before moving to other baby sleep techniques.
Andrew Dolbin-MacNab
Pediasleep LLC
About the Author:

Andrew Dolbin-MacNab is a father, sound-engineer, and the founding member of Pediasleep LLC, a leader in the production of white noise and other soothing sounds to aid the healthy sleep of infants, cosleepers, and parents. Having successfully survived his daughter's early sleep problems with the help of white noise, he is also an expert on infant sleep problems and their solutions. Pediasleep can be found online at http://www.Pediasleep.com.