Low Testosterone

Causes of Low T

causes of low T

Medically reviewed by Dr. Larry Lipshultz M.D

The majority of men believe that low T is a natural consequence of aging. Yes, getting older can be “one” factor in the causes of low T, but basically low testosterone is a lifestyle disorder. That means it can usually be resolved by making lifestyle adjustments. That’s great news for men who are willing to tackle the symptoms of low T head-on and also experience the other benefits of making lifestyle modifications.

Before we look at the numerous causes of low testosterone, let’s bust the “aging equals low T” myth.


Is Aging a Major Reason for Low T?

A team of researchers at the University of Sydney recently announced that the decline in testosterone levels as men get older appears to be the result—and not the cause—of worsening health. The study’s principal investigator, David Handelsman, MD, PhD, explained the findings of their study and the association between aging and low testosterone in this way. “The modest decline in blood testosterone among older men, usually coupled with nonspecific symptoms, such as easy fatigue and low sexual desire, may be due to symptomatic disorders that accumulate during aging, including obesity and heart disease. It does not appear to be a hormone deficiency state.”

Handelsman also noted that “Older men with low testosterone levels do not need testosterone therapy unless they have diseases of their pituitary or testes.” A low percentage of men fall into this category.

It’s true that testosterone levels begin to decline gradually by about 1 percent per year starting at age 30. In fact, that decline is caused by an enzyme called 5-alpha-reductase, which increases its activity level around that time. This enzyme converts testosterone into dihydrotestosterone (DHT), a hormone that you might recognize as the culprit in several other age-related issues affecting many men: hair loss and balding, an enlarged prostate, and an increased risk of cancer. When T is converted to DHT, it also automatically reduces levels of testosterone.

Yet many other factors are responsible for low T, and they are primarily associated with lifestyle choices.

What Causes Testosterone Levels to Decline?

The fact that declining testosterone levels are largely due to lifestyle choices is good news since that means you can take control over these falling numbers. This is true for all men, regardless of age. Every man is unique in the number and degree of factors that can be causing his T levels to drop. Basically, the more healthful lifestyle habits you already possess and the better your overall health, the easier it may be for you to get your T levels to rise or stabilize.

On the other hand, men who make the biggest efforts to tackle the lifestyle factors (including diseases associated with lifestyle) that contribute to testosterone decline can likely notice the biggest rewards. That said, factors that cause T levels to decline include:

  • Diseases, including diabetes, liver disease, kidney disease
  • Use of certain medications, such as antidepressants, antipsychotics, beta-blockers, cimetidine, diazepam, opioids, spironolactone, and statins, among others
  • Poor diet, including one high in sugar, saturated fat, processed foods, animal protein, and cholesterol and low in fiber, fruits and vegetables, and phytonutrients
  • Poor sleep, which includes getting either too much or too little sleep (hint: 7 hours nightly is optimal)
  • Exposure to environmental toxins, such as pesticides, BPA, fungicides, phthalates, mercury, bovine growth hormones, fluoride, monosodium glutamate, and others, which are endocrine-disrupting chemicals and thus have an impact on T levels. These toxins are found in personal hygiene products, food and food packaging, plastic products, household cleaning items, and building materials.
  • Stress, physical and emotional, and failure to manage it effectively
  • Excess alcohol consumption, defined as more than two drinks daily
  • Obesity, as fat is a haven for estrogen, which throws off the ratio/balance of estrogen to testosterone
  • Lack of sufficient physical exercise, which goes hand-in-hand with obesity

Notice that nearly all of these factors have one thing in common: they are preventable or can be managed effectively. They also are related to poor health at various levels, and “poor health may accelerate the age-related decline” in testosterone levels, according to research in the Journal of Clinical Endocrinology and Metabolism. More recent research involving evaluation of blood samples from 325 men to identify testosterone levels over three months concluded that “age-related decline in blood T accompanying non-specific symptoms in older men may be due to accumulating age-related co-morbidities rather than a symptomatic androgen deficiency state [low T].”

References for Causes of Low T:

Feldman HA et al. Age trends in the level of serum testosterone and other hormones in middle-aged men: longitudinal results from the Massachusetts male aging study. Journal of Clinical Endocrinology and Metabolism 2002 Feb; 87(2): 589-98

Sartorius G et al. Serum testosterone, dihydrotestosterone and estradiol concentrations in older men self-reporting very good health: the healthy man study. Clinical Endocrinology (Oxford) 2012 Nov; 77(5): 755-63