How Low Testosterone Affects Your Health

Dropping levels of this male hormone can cause more than sexual problems. It can also affect your mood, weight, and concentration.

Medically Reviewed by Melinda Ratini, MS, DO on December 02, 2012
5 min read

Pete Evans knew something was wrong when he had sudden problems getting an erection. At 52, he had always had an active sex life. Even the bone marrow transplant he underwent in the summer of 2009 had little effect on his libido. Then, six months after the transplant, he lost his ability -- and his appetite -- for sex.

"After the operation, I had tons of energy, great libido. Then suddenly, things just stopped working," Evans (not his real name) says. "I was kind of depressed, too. After all I'd been through and now this."

Finding himself unable to perform was an alarming first for him. When Evans, a retiree who lives in Amherst, Ohio, told his doctor, he received a prescription for Viagra. That didn't help. At a follow-up appointment, he had some blood work done. It showed that his testosterone level had tanked, likely a side effect of one of the post-transplant medications he was taking. This time, his doctor sent him to a urologist, who prescribed a testosterone skin patch to boost the levels of the hormone in his blood. He's now been using patches for about five months.

"I'm feeling more and more confident," Evans says. "Bringing up my testosterone has brought up my mood dramatically. I feel normal in every way."

Evans needed his bone marrow replaced because he has a rare blood disorder called aplastic anemia. His low level of testosterone, however, is a condition he shares with many men his age. The big difference is that Evans's testosterone levels plummeted almost overnight due to complications with his medication.

Age-related loss of testosterone, on the other hand, is gradual, dropping by about 1% to 1.5% per year beginning at age 40. The low testosterone levels that result can leave men feeling less energetic, less self-assured, and less manly.

In some labs, the normal levels (determined by a simple blood test) of a man's testosterone will measure 300 to 1,000 nanograms per deciliter. However, it's important to confirm low levels of testosterone since many men will have normal levels on repeated testing due to fluctuations of the hormone.

"I felt like something had been taken away from me," Evans says, and it wasn't just about the sex. "I didn't have the strength I once had, and I was not able to build muscle mass."

Evans's description resonates with Edmund Sabanegh, chair of the urology department and director of the Center for Male Infertility at the Cleveland Clinic in Ohio. "I look at testosterone as jet fuel. It keeps men running. Diminished mental clarity, motivation, drive -- all of these things can be related to low testosterone."

Testosterone plays a big role throughout a man's life. The hormone is the prime driver of puberty, responsible for the deepening of the voice, the development of muscles, and the growth of pubic hair. Without testosterone, there would be no beards or mustaches since it regulates facial hair. Sperm production falls under testosterone's control. In sum, it's the hormone that makes a man a man, and it is what gives men their appetite for sex.

While a decline in blood testosterone may be a normal part of aging and the most common cause of low testosterone, it is not the only one. Testicular cancer as well as the chemo and radiation used to treat it and other forms of cancer can deplete a man's levels of the hormone. Excess alcohol and certain medications may also be the cause. Pituitary and thyroid diseases as well as injuries to the testes can also drain your testosterone.

Testosterone is more than just fuel for a sex machine. Low testosterone levels can also cause:

  • Decreases in bone density, which can lead to osteoporosis
  • Diminishing ability to concentrate, as well as irritability and depression
  • Increases in body fat, particularly in the midsection where the buildup puts them at heightened risk for type 2 diabetes, heart disease, and certain cancers.


Fortunately, there are effective remedies to raise testosterone back up to a normal level. Sabanegh likes his patients' levels to hover around 300 to 500 ng/dL. Treatment comes in several different forms, each with its own pros and cons.

Deep muscle injections are the oldest and least expensive treatment. Given anywhere from every two to 10 weeks, they give patients the biggest boost in the first few days, after which levels begin to drop. They're not for the needle shy, and they can be painful when receiving the injection itself.

Patches and gels are applied daily to the skin, and the testosterone is absorbed into the bloodstream. They're easy to use, but some men develop rashes, itching, and other skin irritations. Also, they have to be careful that their partners and children don't touch the gel. A nasal gel is now available that eliminates the risk of exposure to others.  

Buccal tablets are placed between the gums and upper lip -- like chewing tobacco (not that anyone should be chewing tobacco). These 12-hour tablets slowly release testosterone into the bloodstream, but they can be bitter-tasting as well as an irritant to your gums.

Subcutaneous (under the skin) implants are the latest treatment in the testosterone-boosting arsenal. Once these implants are in place, they work continuously for about six months. Sabanegh says that infections, bleeding, or bruising can occur at the insertion point, though rarely.

Sabanegh steers patients with sleep apnea away from testosterone therapies since it may worsen the condition. He also discourages men who are trying to conceive a child with their partners. "In some men," says Sabanegh, "testosterone treatment will turn off the body's own testicular function -- both sperm production as well as testosterone production."

Use of testosterone replacement may increase a man's risk of blood clots. It also can accelerate age-related enlargement of the prostate, a condition known as benign prostatic hyperplasia. However, there is little evidence, according to Sabanegh, that testosterone treatments put men at higher risk of developing prostate cancer.

"We used to worry about prostate cancer, that testosterone treatment might accelerate its progress or onset, but that has not been borne out," he says.

Still, your doctor will likely want to keep a close watch on your prostate and monitor it for any suspicious changes for as long as you are taking testosterone. Other potential adverse effects of treatment can include acne and breast tenderness.

Maintaining a normal testosterone level is not simply a matter of choosing and sticking with the right treatment. Getting and staying fit is also essential.

According to Sabanegh, fat speeds up the metabolizing of testosterone. The more fat you carry around, therefore, the faster you'll burn through the already-depleted hormone.

"Your general health makes a difference," Sabanegh says. In other words, if you want to get the most out of your treatment and your testosterone, exercising, eating right, and keeping your weight down must be a big part of the prescription.

Evans is doing just that. In addition to sticking with his testosterone patch, he plays golf every week, walks three miles a day, and works in his garden. He's also keeping active in the bedroom. That makes him a happy man. And he's not the only one who's happy.

"My sex life -- everything -- is good, and so is my wife. She's happy, too."