Summarize this article:

If the person continues to have difficulty falling asleep, you may suggest that he or she visit a sleep specialist. People who visit sleep specialists are those who are complain about lack of sleep quality and/or quantity. Their are 88 different types of sleep disorders, and a specialist will be able to help your friend or loved one tackle their specific sleeping problem.  A primary care physician may refer someone to a sleep specialist based upon symptoms, so their doctor can be their first stop. The sleep specialist will ask a number of questions to determine if the patient needs further testing. The test, called a polysomnogram, measures activity during sleep through electrodes attached to the body. The polysomnogram will measure heart rate, brainwaves, eye movement, muscle tension, air flow, and more. There are a number of possible suggestions that a specialist will make. It may be that they suggest behavioral therapy, for instance changing lifestyle and habits (as mentioned above). It is also possible they will suggest medication to help with sleeplessness, or suggest devices that will make it easier to breath at night. Whatever the suggestions of the specialist, make sure your friend or loved one follows the directions exactly.

Summary:
Consult a sleep specialist. Expect tests at the sleep specialist. Follow the specialist's recommendations.