Although low levels of testosterone affect males of any age, current research focuses especially in low testosterone in adult men. A variety of medical conditions that causes of low levels of testosterone in men, some of them are more obvious, while others are less recognized. Low testosterone causes can be classified in six broad categories: age related, head injury or trauma, testicular injury, medical procedures such as vasectomy, medication and certain medical conditions. In some cases, the exact cause of low testosterone is unknown.
Age related changes in testosterone levels
The amount of the testosterone in the body decreases with age. For example the average
testosterone levels in men 15 to 24 years of age is around 750 ng/dl (with upper limits going as high 1,000 to 1,200 ng/dL), in men age 35-44 it is 650 ng/dl, in the 65-74 age group it is 500 ng/dl and in men over 85 it drops to around 400 ng/dl.
Head injury or trauma
A stroke, head injury or any other condition causing loss of oxygen in the brain can cause low testosterone. This is because the hypothalamic pituitary gonadal axis can be damaged in the process. The hypothalamus and pituitary gland are key brain structures that send signals to the testicles to produce more testosterone. When the brain is affected, this axis is disrupted, and the testosterone levels may drop.
Testicular Injuries/Diseases
A traumatic injury of the testicles can be one of the low testosterone causes, since testis are part of the hypothalamic pituitary gonadal axis. Testicular cancer as well as chemo therapy recommended for this condition can also lower the testosterone levels.
Vasectomies Can Lower Testosterone
Although the link between vasectomy and low testosterone levels is still controversial, preliminary studies suggest that there may be a connection, and in the future this procedure may be recognized as a contributory factor to low testosterone levels. After getting a vasectomy, the body develops an autoimmune (self-attacking) disorder, leading to anti sperm and other complex antibodies in the blood.
Medication
Medication may cause low testosterone levels through three main mechanisms. They may damage the nerves, the vessels or interfere with the endocrine system. Well known drugs that are linked with low testosterone levels are certain drugs used for high blood pressure such as Inderal, Clonidine and Lasix; antidepressants belonging to the main three classes: SSRI, tricyclic antidepressants and MAO inhibitors; tranquilizers and antipsychotics and a group of drugs called anticholinergics which includes the commonly used drug Benadryl.
Other medical conditions
Certain hormonal disorders, infections including HIV/AIDS, chronic liver or kidney conditions, type 2 diabetes and obesity may also cause low testosterone levels. In some cases, the exact cause of low testosterone is not known.
Considering that this issue is affecting an increasingly number of men, it often goes unrecognized and there are so many causes that can lead to low testosterone, it is important to consult a doctor, and get appropriate testing and treatment. Psychological factors and stress as well as diet can also impact the hormones so it is important that you look into making healthy lifestyle changes as well.
References:
http://men.emedtv.com/low-testosterone/causes-of-low-testosterone.html
http://men.webmd.com/features/low-testosterone-explained-how-do-you-know-when-levels-are-too-low
http://www.mens-hormonal-health.com/cause-of-low-testosterone.html
