Virilization is the development of secondary sexual characteristics which are usually associated with males, including increased musculature, baldness, body hair, a flattened chest, and a deep voice. In male fetuses and developing boys, virilization is a natural process. The sexual secondary characteristics which emerge as a result of sexual differentiation cause men in general to look slightly different from women, and in the case of infant development, virilization is involved in the development of male genitals, a primary sexual characteristic.
In female fetuses and women, virilization is usually a cause of concern because it indicates that overexposure to androgens is occurring and that the patient may be at risk for health problems. There are a number of things which can cause virilization, and it can be accompanied with a variety of symptoms. In addition to the developmental changes discussed above, virilization in women also leads to clitoral enlargement.
In infants, the cause is usually prenatal exposure. If a woman takes anabolic steroids while pregnant or is exposed to other sources of androgens, including endocrine tumors which lead her to produce excess androgens, a female fetus may undergo virilization. When male sexual characteristics are noted in a female infant shortly after birth, it is usually believed to be the result of prenatal exposure. Some testing may be conducted and treatment can be provided on the basis of the test results.
In girls and women who start to develop male characteristics, virilization can be a result of taking anabolic steroids or it can be caused by an adrenal tumor which leads the adrenal gland to start overproducing androgens. In this case, the treatment is to remove the source of excess androgens and allow the woman's endocrine system to regulate and balance itself. There are also cases in which people deliberately induce virilization, as seen among female to male transsexuals who want to develop male characteristics to feel more comfortable in their bodies.
Treatment for virilization is usually overseen by an endocrinologist. Endocrinologists specialize in hormone disorders and treatments which may require administration of hormones. They can run tests to check hormone levels and adjust treatment dosages to make sure that their patients are provided with appropriate levels of hormones for treatment. If an adrenal tumor is the root cause, a surgeon will also be required as part of the treatment plan involves removal of the tumor so that the patient's overenthusiastic adrenal gland will stop producing an excess of androgens.