Insomnia is a common problem in older people, especially in patients with mild cognitive impairment (MCI) whose circadian rhythm is often compromised. Insomnia exerts such a toll on caregivers that it is frequently the primary reason for seeking to institutionalize their loved ones. Three different types of insomnia are recognized: sleep-onset or initial insomnia, sleep maintenance or middle insomnia, and early morning awakening or late insomnia. Nocturnal hypoglycemia, as a cause of middle insomnia, is the main focus of this case study. Other types of insomnia are also briefly reviewed. The management of insomnia is then discussed including sleep hygiene, the usefulness and potential drawbacks of dietary supplements, nonprescription over-the-counter preparations and prescription hypnotics. Sleep architecture is then briefly reviewed, emphasizing the importance of its integrity and the role of each sleep stage.