[Sexuality in old age].
The research on sexual behavior of old people is still suffering from grave deficits. In spite of this it can be said that the biological bases in men and in women are characterized by lower speed and intensity. The old people's attitude towards sexuality in general and their own sexuality is still less liberal than the attitude of younger persons. The frequency of sexual intercourse decreases, mainly because of lack of partners or because of health problems. There are many other forms of sexual behavior; especially, the importance of tenderness is increasing. A theoretical model of factors influencing the sexuality in old age is presented. Practical considerations concerning the prevention in young and in older people, treatment of older people in the physician's practice and their living in institutions conclude the article.