To gain certification a medical doctor must go through specific training in all areas of sleep medicine and pass a sleep medicine exam.
One way to be certain you're getting a certified specialist is to request one at a sleep lab that's accredited by the American Academy of Sleep Medicine (AASM), which requires a certified specialist in every lab. SleepCenters.org offers a complete list of accredited sleep labs.
Sleep specialists typically have a specialty in one field. Behavioral sleep medicine (BSM) specialists, for example, have extensive training in treating chronic insomnia. The AASM keeps an updated list of BSM specialists on their website, although there are only about a hundred certified throughout the country.
It's often not possible to see doctors who specialize in your particular sleep issueif you even know what your condition isbut certified sleep specialists have the training to evaluate everything from breathing-related disorders to mental and neurological issues.
If seeing a certified sleep specialist isn't financially or geographically feasible for you, a pulmonologist, neurologist, or otolaryngologist may be able to help you identify your sleep problem.