Hi everyone, this is Dr. Aniruddha Railkar, the award-winning author of the book The Great Testosterone Myth: Honest Facts No Hype. Today I would like to talk to you about diagnosis, symptoms and causes of low testosterone.

As we age, there is a natural tendency to lose testosterone. But other factors such as obesity, high blood sugar and exposure to environmental pollutants can also cause low testosterone. But it is important to recognize the difference between low testosterone due to aging and a medical condition called hypogonadism. It has also been referred to as andropause, androgen deficiency or late onset hypogonadism.

Diagnosis of medical or clinical low testosterone (hypogonadism) is done by checking the levels of total testosterone in blood. Total testosterone is comprised of testosterone bound to proteins (which is not bioavailable) and free testosterone (which is bioavailable). It is believed that decrease in free testosterone has a greater effect than decrease in total testosterone. If the total testosterone level is less than or equal to 300 nanogram per deciliter, then you have hypogonadism. As for the levels of free testosterone, normal range is 150-250 picogram per deciliter. There is another test that measures free testosterone. If that test shows that free testosterone is less than 150 picogram per deciliter, it may be hypogonadism. Another diagnostic test is a qualitative test. It is called Androgen Deficiency in Aging Males or the ADAM test.

It was designed by Dr. Morley, the director of endocrinology and geriatrics at the St. Louis University School of Medicine. It consists of 10 questions and they are in my book (Insert Link to my book on Amazon).

The three main symptoms of hypogonadism are decrease in muscle mass and strength, decrease in bone mass and osteoporosis and increase in body fat around the middle of the body. Other qualitative symptoms are loss of libido, lack of sexual desire, sleeplessness, forgetfulness. But as mentioned before, they are difficult to measure and distinguish from symptoms associated with aging. As we age, the testosterone levels gradually decrease about 1% every year after age 30. Hypogonadism can be divided into two types:

  1. Primary– It is also called primary testicular failure and as the name suggests, this type is caused by some problem with the testicles.
  2. Secondary– This type is caused by a problem with the hypothalamus-pituitary axis.

Either type of hypogonadism can be caused by an inherited genetic defect or a problem or ailment that occurs later in life such as a disease or accident. In my book (Insert Link to my book on Amazon), I have detailed description of the causes.

In addition to medical factors, there are other factors that can cause low T. A study by Northwestern University in 2011 showed that fatherhood lowers a man’s testosterone. The study which lasted almost 5 years, followed 624 males in their early to mid-20’s before and after they became fathers. Some doctors suggest that demands of fatherhood result in lack of sleep and lack of exercise consequently lowering testosterone.

Environmental pollutants can also affect testosterone levels. A series of studies carried out by researchers at the University of California at Berkeley showed that atrazine a common fertilizer, can convert male frogs into female frogs. Other studies in fish, amphibians, birds, reptiles, laboratory animals and human cell lines have shown that atrazine levels as low as parts per billion can interfere with testosterone and estrogen.

Last but not least factors such as smoking, diabetes can also affect testosterone levels.