According to a long term study done, it suggest that dry mouth is common in those over the age of fifty particularly in older women. In the Swedish study, started in 1992 researchers sent questionnaires to every 50-year-old in 2 Swedish counties. Fifteen years later, they sent the same questions to every 65-year-old in those counties. They also sent them to a sample of 75-year-olds.

The study showed that in every age group, dry mouth was more common in women than in men. The authors speculate that the higher prevalence of dry mouth in women may be the result of decreased saliva production in the mouth following menopause. Dry mouth occurred more often as people got older, and more at night than during the day.