The time to see a doctor especially trained in sleep disorders is when you have had trouble sleeping for more than a month or if you are tired during the day for unknown reasons. If you have trouble falling asleep or staying asleep, it is important to have the cause evaluated by a sleep specialist (and it may require sleep studies). You and your primary care physician should not assume that you have insomnia. Recent studies show that a high percentage (30-50%) of people diagnosed with insomnia actually have another sleep disorder, such as obstructive sleep apnea. Also, it is very important to have your nocturnal breathing pattern evaluated before starting any sleeping aid, because these medications may depress your respiratory drive.