Lots of men worry they have "low t." David Cordova really does.
"She said I think you have a testosterone deficiency. I said, 'Can't happen to me being the machismo man that I want to be,'" he said.
At 56, he was facing osteoporosis. To reverse that, his doctor put him on testosterone shots. But first, he had a blood test to check his testosterone level. That's not always the case.
"We see a substantial percentage of younger men, men in their 40s, who begin testosterone therapy without even really knowing if they need it," said Dr. Jacques Baillargeon, who conducted the UTMB testosterone study.
His UTMB study found one in four men start taking testosterone without knowing if they even need it. And he says new prescritions for testosterone have increased 300 percent in the past decade, even more for younger men.
The problem is if a man takes testosterone and doesn't need it, he may be exposing himself to health risks like an increased risk of prostate cancer, stroke or heart attack.
"We don't know the long term risks for prostate cancer. There are a lot of studies that have conflicting results," Dr. Baillargeon said.
UTMB is now conducting a study on the risk of heart attack and stroke among testosterone users. And other studies are looking at the prostate cancer risk.
Until they have better answers, Cordova is being careful.
"We're playing it safe because every six months they are monitoring me," Cordova said.
But he's worried many young men don't realize the risks.