The testes (testicles) make testosterone. Testosterone is the essential male sex hormone that regulates fertility, muscle mass, red blood cell production and fat distribution in body, hence play a vital role in overall health and well-being in men. Testosterone aids bring on the physical changes that change a boy into a man, called as puberty. Few of the changes as: growth of the penis and testes, facial, body hair, deepening of the voice, building muscles, strong bones, etc. Without adequate amounts of testosterone, men become infertile, since it promote development of mature sperm. Testosterone reside to a class of male hormones called androgens, which are occasionally also called steroids hormones or anabolic steroids.  Testosterone being a male sex hormone, but it also contributes to sex drive, bone density, and muscle strength in women. An excess of testosterone in women can also cause to situation like male pattern hair loss, deepening in voice, irregular menstrual cycles and infertility. The brain hypothalamus and pituitary gland control testosterone levels by the testes. it is produced in men’s testicles largely, the adrenal glands also produce small amounts of it. After produced, it flow through the blood to carry out its various essential functions. The hypothalamus signal pituitary gland quantity of  testosterone to produce, and pituitary gland passes the message on to the testes via chemicals and hormones in the bloodstream.

Testosterone levels change from hour to hour. They likely to be highest in the morning and lowest at night. Its levels are high by age 20 to 30 and slowly go down after age 30 to 35.
Low testosterone levels can lead to various possible symptoms as below:

  •  Reduced sex drive
  • Erectile dysfunction or impotence
  • Increased breast size
  • Lowered sperm count
  • Hot flashes
  • Depression, irritability and inability to concentrate
  • Shrunken and softened testes
  • Loss of muscle mass or hair
  • Bones becoming prone to fracture