What’s causing your TDS

Men can develop TDS for a number of reasons and sometimes the specific trigger is unknown.

  • ED and Type 2 diabetes which are associated with low levels of testosterone in men31,26
  • Disturbances of testicular function due to other disease (e.g. viral orchitis, infections, drug induced, radiation etc.) 25
  • Genetic causes (e.g. Klinefelter’s syndrome)25
  • Aging (e.g. a mixture of reduced testicular testosterone production and pituitary function)25

There are three main types of TDS:

Primary TDS is caused by low testosterone due to a problem within the testes. This may be for a genetic reason such as Klinefelter’s syndrome, in which the testes develop poorly and testosterone doesn’t rise during puberty as it usually would, so a man’s appearance seems less typically masculine.

It can also be caused by physical damage to, or removal of, one or both of the testes. Illnesses such as mumps, cancer, liver or kidney disease and diabetes can also affect the testes and cause primary TDS.

Secondary TDS occurs when the male hormone system goes out of balance or doesn’t work effectively. This hormone system is regulated by two parts of the brain – the hypothalamus and the pituitary gland, which stimulate the testes to produce testosterone and sperm. A breakdown or imbalance at any point in the system can lead to a reduced level of testosterone.

Secondary TDS can also be due to genetic causes such as Kallmann syndrome, or conditions such as a pituitary tumour, malnutrition or long term illnesses such as kidney failure or diabetes. Depending on the cause of TDS, symptoms may occur rapidly or gradually, sometimes taking years to become noticeable.

Late-onset TDS is when a man’s testosterone level falls lower as he gets older. Although a decline with age is natural, some men’s testosterone levels may fall too low due to reduced function of the testes, plus less hormonal stimulation from the brain. Because the onset of symptoms is often gradual, late onset TDS may go unnoticed for some time.

Associated conditions

Erectile dysfunction is often associated with TDS as it has been shown that over a third of men who have difficulty getting an erection may also have TDS17. Studies have confirmed that adequate testosterone levels are important for sexual function31.

If you have ED and some of the features of TDS you should consider getting your testosterone levels checked - especially if your current ED treatment isn’t effective, as sufficient levels of testosterone can restore or enhance your response to ED tablets18.

Type 2 diabetes is associated with low levels of testosterone in men26. A UK study suggests that 42 percent of men with Type 2 diabetes have low testosterone levels (below 12nmol/L) associated with symptoms26. Low testosterone levels have been independently associated with insulin resistance in men with either Type 2 diabetes or Type 1 diabetes15.

Benefits of treatment

  • Your testosterone levels could be restored to normal levels
  • Your libido and energy levels will probably be increased
  • You may also see an improved erectile function (if taking a treatment for erectile dysfunction)
  • Relieving your symptoms could improve your quality of life
  • Improved muscularity and hair growth will show your treatment is working
  • Over time, your mood should also improve

Testosterone replacement therapy is not suitable for everyone. Like any medication, it is associated with side effects which should be discussed with your doctor, who will take into account your general health including any cardiovascular problems or diabetes. It is not to be used in patients with prostate or breast cancer or those allergic to the constituents of the medication. Please see the section on Important things to know about Testosterone Replacement Therapy for further information.