Several studies have suggested that individuals with long or short sleep durations are at greater risk for adverse outcomes relative to individuals sleeping 7-8 hours a night. The mechanisms leading to these results have never been fully explained, but individual differences in how long an individual sleeps are usually considered to reflect lifestyle rather than disease. Alternatively, individuals may sleep a particular amount because of characteristics of their sleep physiology. In this study, we examined population-based data on the associations between sleep duration and several symptoms of sleep-related disease, reported snoring and daytime sleepiness. Results from 1877 independently living individuals between the ages of 50 and 65 years suggested that long, but not short, sleep durations were related to greater reported snoring. Higher levels of reported snoring and daytime sleepiness, but not habitual sleep duration, were related to measures of disease and lower psychosocial function. We suggest that future epidemiologic studies use such additional items as potential indicators of sleep-related disease.