Testosterone is a male reproductive hormone. In the males, it is predominantly produced by the testis. Females also have testosterone in their bodies as well which is mainly produced by the ovaries. The adrenal glands also produce testosterone in small quantities both in males and females. It contributes to sexual functions in females though its quantity is lower than in males. Women have one tenth the amount of testosterone as compared with men but by age forty, their level can rise to half that of a twenty year old man. As women get older, they produce less estrogen and more testosterone. Women who are in menopause and post menopause have the highest level of testosterone.
Typically, during youth from age 14 to 20 years free testosterone levels are at their highest. However, as men age, its level gradually diminishes with age. From the age 25 years to 95 years, the testosterone level will ranges from 700 ng/dl to 350 ng/dl in healthy males, with a decline of 50 ng/dl in a decade.
A table mentioned at the end of the hub shows different testosterone levels at different ages in healthy males
Effects in males-
- Prenatal growth- It promotes prenatal growth of male specific body parts during development in the womb.
- Physical characteristics- In puberty, its levels increase in boys causing more manly characteristics to develop such as body hair, pubic hair, penile growth, testicular growth, voice changes and sperm production. It also brings on nocturnal emissions or wet dreams in youngsters. It causes growth of a prominent Adam’s apple, changes in the contours of the bones of face, jaw, eye brows providing manly features. It also activates an increase in the length of bones, thus increasing overall height of a person.
- Sexual function- It plays a role in fertility, libido, semen production, penile erection and ejaculation. It continues to perform sexual function throughout life.
- Anabolic effect- Its anabolic effects produce increase in bone and muscle mass, providing more strength to men over women who have less natural testosterone.
Effects in females-
In females, the effects of testosterone are variable. The main drivers of female libido are testosterone and its metabolite dihydrotestosterone. Some women who have high levels of testosterone are more prone to having sons instead of daughters but this is controversial. Women with high level of the hormone have male hair patterns on face and chest, deeper voice, increased muscle mass, weight gain and acne. Some women develop these changes for the first time after menopause due to rising levels of the hormone. Such women after menopause with high testosterone levels are at risk of developing heart disease. Testosterone has the power to decrease fat mass in women and it can also promote insulin resistance.
In some women as they grow old, the levels of testosterone go down since their ovaries start failing. Many women have mid to high range of the hormone as they age making them vibrant and strong while approaching the menopause.
In women, testosterone increases vaginal lubrication by increasing nitric oxide in the arteries supplying the organ. A woman with high testosterone possesses a lean body, attractiveness and high energy. Testosterone nurtures sexual desire and heightens a woman's sensitivity to sexual stimulation.
Changes in males due to testosterone decline-
As mentioned above, there is a gradual decline in the levels of testosterone in males from age 25 years onward, with an average decline of 50 ng/dl in a decade. Majority of males develop some drastic changes after 40 years of age, which result from the decline of the testosterone, leading to a midlife crisis called “andropause” or “male menopause”.
The age–related physiological decline in testosterone levels cause physiological changes, which include loss of muscle mass and strength, decline in physical functions, sexual dysfunction and psychological changes. The common changes are enunciated below-
- General tiredness
- Night sweats and palpitations
- Nervousness, irritability, mood changes or depression
- Erectile dysfunction
- Cognitive challenges like age-related memory loss and certain dementia and visual-spatial cognitive decline
- Decline in productivity
- Emotional lability
- Personality changes
- Boyish behavior
How to decrease the testosterone decline in males-
An arrest of the decline in testosterone levels can be achieved with the following.
- A well-formed exercise schedule incorporating aerobic and strength training exercises should be performed regularly. High intensity aerobic exercise and strength-training raise the levels of testosterone in the body. In other words, the more lean muscle mass a person has, the more will be one’s testosterone level in the blood.
- Overweight and obese persons should reduce their weight to achieve the ideal weight and try to maintain it throughout life. Incidentally, low testosterone level induces obesity in men.
- Smoking is another important cause for the decline of testosterone. So one should quit smoking.
- High cholesterol levels in blood also contribute to its decline. So it is necessary for a person to maintain a normal level of cholesterol in blood by adopting healthy life- style choices and drugs if necessary.
- Depression is also a risk factor for decline in testosterone level.
- Regular sexual activity increases testosterone levels. That is why married men have higher level of the hormone.
- Alcohol also declines the levels of the hormone. Alcoholic men have decreased sexual functions such as impotence and infertility. Alcohol acts as a testicular toxin. In healthy non-alcoholic men, alcohol intake may cause transient acute decrease in blood testosterone levels. So one should abstain from drinking alcohol in order to preserve normal levels of testosterone in blood.