Low Testosterone (Low-T)

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Low testosterone (Low-T) definition

Testosterone is a hormone required for male development and is produced primarily in the testicles. It is responsible for building muscle and bone mass as well as sperm production and sex drive. It influences male pattern fat distribution, bone density, and red blood cell production.

Lack of or underproduction of testosterone either directly due to decreased production in the testes or indirectly due to lack of stimulation of the testes to produce testosterone by the pituitary gland is called hypogonadism and is a medical condition requiring treatment.

In the normal developing male, testosterone peaks during early adulthood. Once you reach age 30, testosterone levels slowly decline by approximately 1% a year. This is a normal part of aging.

What are the "normal" levels of testosterone in men?

The low limit of testosterone levels in men is about 300 nanograms per deciliter and the upper normal limit is approximately 1000-1200 ng/dl. A low level needs to be investigated further to distinguish it from normal aging.

What causes low testosterone (Low-T)

Some of the conditions that can lead to a low level are:

  • Obesity
  • Diabetes (type 2)
  • Chronic medical conditions (especially liver or kidney disease)
  • Hormonal disorders
  • Infections

What are the symptoms of low testosterone (Low-T)?

It is important to distinguish between a normal decline of testosterone levels and hypogonadism.

Signs and symptoms of low testosterone include:

Although testosterone therapy helps with hypogonadism, whether it helps in the reversal or slowing of normal effects of aging and lower testosterone levels is unclear. Several published research articles have conflicting results and more research is needed to make a final determination about the use of testosterone for healthy aging males.

Medically Reviewed by a Doctor on 9/26/2013

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Low Testosterone Symptoms

Low Testosterone Symptoms in Men & Women

Symptoms of low testosterone in males depends upon when the low levels occur. In men, low testosterone may lead to:

  • infertility,
  • decrease sexual function and desire,
  • erectile dysfunction (ED),
  • hair loss,
  • decreased muscle mass, and
  • osteoporosis.

Symptoms of low testosterone levels in women include:

  • hot flashes,
  • irritability,
  • loss of sexual desire,
  • sleep disturbances,
  • loss of muscle mass, and
  • decreased bone density (osteoporosis).