Masturbation (sukkavissaṭṭhi) is the act of stimulating one’s own sexual organs (sambādha) to the stage of orgasm (adhikavega). In the Kāma Sūtra male masturbation is called ‘seizing the lion’ (simhākāranta). Some people during the Buddha’s time believed that masturbation could have a therapeutic effect on the mind and the body (Vin.III,109), although the Buddha disagreed with this. According to the Vinaya, it is an offence of some seriousness for monks or nuns to masturbate (Vin.III,111) although the Buddha gave no guidance on this matter to lay people. However, Buddhism could agree with contemporary medical opinion that masturbation is a normal expression of the sexual drive and is physically and psychologically harmless, as long as it does not become a preoccupation or a substitute for ordinary sexual relations. Guilt and self-disgust about masturbating is certainly more harmful than masturbation itself.
See Sexual Behaviour.