Women naturally produce small amounts of testosterone, and a high amount usually indicates a medical abnormality. High testosterone can cause a number of physiological, cosmetic and psychological changes in females, and may also lead to serious health risks.
Testosterone is a naturally occurring steroid hormone that the ovaries and adrenal glands of women produce naturally in very small amounts. It causes both anabolic (tissue-building) and androgenic (masculinising) effects.
Doctors prescribe testosterone to treat a number of medical conditions, most of which affect men (hypogonadism, hormone replacement therapy), but testosterone is also used to treat breast cancer in women, and experiments have been conducted using testosterone to treat pre- and post-menopausal changes in mood, energy, bone density and body composition.
The diagnostic website diagnose-me.com reports that the endocrine disorder polycystic ovary syndrome (PCOS) is the most common cause of high testosterone in women. PCOS causes cysts to form in the ovaries, and five per cent of all women will experience this condition during their lives. High testosterone in women may also result from ovarian cancer and diseases, injury or external conditions (such as stress) that cause low oestrogen levels.
High testosterone levels may also occur in women taking anabolic steroids for sport or bodybuilding, and in patients with gender identity disorder who take steroids to transition from female to male.
Testosterone builds muscle by binding to androgen receptors in muscle cells, where it increases the rate of nitrogen synthesis. It also stimulates fat loss and affects the distribution of adipose (fatty) tissue throughout the body. Because of these effects, women with high testosterone levels may experience changes in their body composition that makes their physiques resemble those of adult men.
Also, women with high testosterone are likely to experience the development of masculine characteristics, which can include hirsutism (the growth of excess facial and body hair), particularly upon the chest and stomach. High levels of testosterone in women may also cause acne, oily skin, male-pattern baldness, increased perspiration and a deepened voice.
Women with high testosterone may experience an elevated libido and their high levels of testosterone may also cause an enlarged clitoris, which might be irreversible. High levels of testosterone can also disrupt a woman's menstrual cycles, even causing them to stop completely.
Other Physiological Changes
Excess testosterone shows a strong propensity to damage the liver, and may cause peliosis hepatitis, a serious condition in which blood-filled cysts form inside the liver and/or spleen. Drugs.com reports that testosterone can alter liver levels, and cause the body to retain excess sodium and water, putting additional strain on the liver and kidneys.
Women with high levels of testosterone may experience an aggravation of existing heart disease, and changes in blood serum cholesterol that may lead to coronary disease, high blood pressure and arteriosclerosis. High levels of testosterone in diabetic women may also affect their blood sugar levels and thereby disrupt the activity of insulin treatments.
High levels of testosterone can cause psychological effects that range from moodiness, depression, aggression, irritability and excitability. Also, in a study entitled "Gender differences in financial risk aversion and career choices are affected by testosterone," and published in the August 24, 2009 issue of the Proceedings of the National Academy of Sciences, researchers at the University of Chicago showed that women with higher levels of testosterone take more risks and engage in more thrill-seeking behaviour.