The natural desire for sexual intercourse. Lack of desire or diminished libido may occur in any general medical illness, as well as in endocrine diseases, where there is a lack of production of the sex hormones. The strength or weakness of the sexual drive may be associated with psychiatric diseases; it may also be the result of certain drugs. It must be distinguished from male IMPOTENCE, where the desire for intercourse is normal but the performance is defective due to inability to achieve or maintain an erection.