Sleep medicine deals with the causes, diagnosis and treatment of sleep disorders. A sleep medicine physician treats problems such as sleep apnea and snoring, insomnia and narcolepsy. Sleep apnea is when a person actually stops breathing for a few seconds during sleep, and is usually accompanied by loud snoring. Narcolepsy is a disorder of the central nervous system, and is characterized by excessive daytime sleepiness, and a tendency to sleep at inappropriate times, even if the person gets adequate nighttime sleep. Also considered sleep disorders are periodic limb movements and restless legs.

Treatment includes overnight study in a sleep center, where technicians observe, monitor, and analyze brain activity, respiratory function, muscle function and other variables that help diagnose complex sleep disorders. Sometimes a physician may fit a patient may with a device to measure a person's activity, their environmental temperature, light levels and mood state, all recorded by a computer the size of wrist watch. This allows the physician to get objective, accurate data on the patient's daily life, and help to assess sleep problems.

Doctor density varies by specialty and location. Arizona has 21 practicing sleep medicine doctors. Broken out by city, sleep medicine doctor density in Chandler is 2, in Dewey is 1, in Gilbert is 1, in Glendale is 1, in Mesa is 1, in Nogales is 1, in Phoenix is 3, in Prescott is 1, in Scottsdale is 3, in Sun City is 2, in Sun City West is 1, in Surprise is 2, in Tucson is 6, and in Yuma is 2.

Arizona has many famous tourist attractions and parks, including the Hoover Dam and Lake Mead, which was created when the dam was built. The Grand Canyon draws millions of visitors each year, and Phoenix, Scottsdale, Flagstaff each draw their own sun-seeking winter vacationers. Visit the world-famous O.K. Corral in Tombstone. Arizona’s population is 5,939,292, and Phoenix, the capital city, is home to a majority of those people. Entertainers Linda Ronstadt, Stevie Nicks, and Tanya Tucker were born here, along with architect Frank Lloyd Wright and former Supreme Court justice Sandra Day O’Connor.

According to 2005 Census estimates, Arizona has a population of 5,939,292. Of this population, 1,535,805 are under the age of 18 and 754,345 are at or above the age of 65.