Vaginal atrophy, also called atrophic vaginitis, is thinning, drying and inflammation of the vaginal walls due to your body having less estrogen. Vaginal atrophy occurs most often after menopause, but it can also develop during breast-feeding or at any other time your body's estrogen production declines.
For many women, vaginal atrophy makes intercourse painful — and if intercourse hurts, your interest in sex will naturally decrease. In addition, healthy genital function is closely connected with healthy urinary system function.
Simple, effective treatments for vaginal atrophy are available. Reduced estrogen levels result in changes to your body, but it doesn't mean you have to live with the discomfort of vaginal atrophy.
Source: http://www.mayoclinic.com