Impotence is the inability of a person to perform sexual intercourse. Sterility is the inability of the male to beget children, and in the female the inability to conceive children. About 10 to 15% of all married couples are involuntarily sterile.

A person can be sterile without being impotent, or he can be impotent without being sterile, or both may co-exist. Frigidity is the inability to initiate or maintain the sexual arousal pattern in the female. Ejaculation which occurs immediately before or immediately after penetration is termed premature ejaculation. Sexual dysfunction is impairment either in the desire for sexual gratification or in the ability to achieve it.

The question of impotence and sterility may arise in:

(A) Civil :

1. Nullity of marriage,
2. Divorce,
3. Adultery,
4. Disputed paternity, and legitimacy,
5. Suits of adoption, and
6. Claim for damages where loss of the sexual function is claimed as the result of an assault or accident.

(B) Criminal :

1. Adultery,
2. Rape, and
3. Unnatural offences, where impotency is pleaded as a defense.

Possible Causes:

1. Age :
2. Defects of Development and Acquired Abnormalities :
3. Local Diseases :
4. General Diseases :
5. Psychical Causes :

Emotional disturbances are a common cause of temporary impotence. Fear of impotence or fear or inability to complete the act is common cause of temporary impotence but usually they are soon overcome. Disgust of the sexual act or dislike of the partner may cause temporary or permanent impotence.

Anxiety, guilt sense, timidity, depression, excessive passion and sexual overindulgence produce temporary impotence.

Quoad is an individual who may be impotent with one particular woman (quoad=as regards) but not with others. Psychological-causes of impotence greatly outnumber all other causes.