Libido

Libido in its common usage means sexual desire, however more technical definitions, such as found in the work of Carl Jung, are more general, referring to libido as the free creative, or psychic, energy an individual has to put toward personal development, or individuation.

Psychology
Sigmund Freud introduced the term and pointed out that libido is the instinctual energy or force that can come into conflict with the conventions of civilized behavior. It is the need to conform to society and control the libido, contained in what Freud defined as the Id, that leads to tension and disturbance in both society and the individual. This disturbance Freud labelled neurosis. Thus, libido has to be transformed into socially useful energy, according to Freud, through the process of "sublimation".

Libido is generally considered synonymous with such concepts as élan vital and psychophysiological energy; related concepts from Eastern philosophy include Kundalini and Tantra.

Libido can also be classified as the urge to create life. For humanity, the natural way in which this occurs is through sex. However at a deep subconscious level, the two can be merged as one, given the reason in evolutionary terms for sexual attraction and sex drive. Using this term, the antonym of libido is destrudo.

See also Eros (Freud)

Physiology
Physicians and psychiatrists consider reductions in libido to be a type of sexual dysfunction and treat it as a medical problem. For example, decreases in libido are linked to decreases in naturally produced testosterone (in both men and women) or estrogen (in women). Hormone deficiencies that cause libido decrease are treated by hormone replacement therapy.

Many medical conditions or treatments also cause decrease of libido. Surgery, fatigue, psychiatric conditions (such as depression or anxiety), and pain can lead to lower libido. Some medications also produce drops in libido (such as SSRIs). Sometimes the libido decrease from SSRIs can be permanent (see PSSD article).

Libido decrease is also associated with aging and pregnancy.