Testosterone is the primary sex hormone and anabolic steroid in males. In male humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristics such as increased muscle and bone mass, and the growth of body hair
Normal testosterone levels in men are around 280 to 1,100 nanograms per deciliter (ng/dL). Women secrete much lower amounts, with normal levels considered to be between 15 and 70 ng/dL. The level of hormones produced in the body varies each day and throughout the day. Testosterone levels are highest in the morning.
Normal levels of testosterone have multiple functions on the overall health of women:
It keeps bones healthy. The correct amount of testosterone supports bone growth and strength, while too much or too little can harm them. According to a review published in November 2016 in the journal Clinical Interventions in Aging, studies show that both testosterone and estrogen are essential for bone formation.
It promotes cognitive health. According to guidelines published in October 2014 in the Journal of Clinical Endocrinology & Metabolism, testosterone has a neuroprotective effect in women. One study showed that postmenopausal women with Alzheimer’s disease had lower levels of testosterone and estrogen than the control group. Another found that higher testosterone levels in the plasma of premenopausal women was linked to better performance in mathematical and spatial-relations tasks.
It maintains sex drive. Testosterone is known as a male sex hormone, but women have levels of the hormone in their system as well — just as men have low levels of estrogen in theirs. The hormone is part of what drives desire, fantasy, and thoughts about sex, and even helps provide the energy for sex in women.
Testosterone imbalances in women can affect their physical appearance and overall health.
Symptoms of high testosterone in women include:
- deep voice
- excess hair on the face and body
- increased muscle mass
- irregular periods
- larger-than-normal clitoris
- loss of libido
- mood changes
- reduction in breast size
- thinning hair
Severely high levels of testosterone in women can cause obesity and infertility.
Low testosterone can cause one or more of the following symptoms in women:
- muscle weakness
- sleep disturbances
- reduced sex drive
- decreased sexual satisfaction
- weight gain
- fertility issues
- irregular menstrual cycles
- vaginal dryness
- loss of bone density
It is important to note that research in this area is still limited.
Because the symptoms linked to low testosterone are so common, a doctor will look for signs of other issues or conditions before making a diagnosis.
The doctor may check for:
- chronic stress
- thyroid disease
- transition to menopause
Among women, perhaps the most common cause of a high testosterone level is polycystic ovary syndrome (PCOS). This disease is common. It affects 6% to 10% of premenopausal women.The ovaries of women with PCOS contain multiple cysts. Symptoms include irregular periods, reduced fertility, excess or coarse hair on the face, extremities, trunk and pubic area, male-pattern baldness, darkened, thick skin, weight gain, depression and anxiety. One treatment available for many of these problems is spironolactone, a diuretic (water pill) that blocks the action of male sex hormones.
Women with high testosterone levels, due to either disease or drug use, may experience a decrease in breast size and deepening of the voice, in addition to many of the problems men may have.