Concussions on the playing field may lead to erectile dysfunction (ED) and low testosterone (T) levels later in life, suggests a new study of retired football players.

Concussions and male sexual problems tend to occur together, the correlational study found, though it does not show that concussions are causing the problems. But taken along with other reports of higher ED incidence and hormonal problems in men with head trauma, such as those in the military, it's a call to look more closely at whether concussions are responsible.

It also means that people with head injuries should to talk to their doctors about any sexual problems they may be having — and that doctors should ask about them.

The good news is that ED is easily treatable. And getting it treated is important because ED can signal the presence of other health problems.

The authors suggest that injury to the brain's pituitary gland might be to blame.

Researchers from Harvard Medical School and the Harvard T.H. Chan School of Public Health looked at over 3400 former NFL football players both young and old, ranging from 24 to 89 years of age. All were asked about their concussion history and whether any medical personnel had ever recommended or prescribed medication for ED or low T.

As a man's reported concussion symptoms rose, so did their odds of reporting either erectile dysfunction or low T.

When men who reported the highest number of concussion symptoms were compared to men who reported the fewest, they were nearly two and a half times more likely to also report having received a recommendation for or currently be taking medication for low T .

Similarly, men with the most concussion symptoms were nearly two times more likely to report receiving a recommendation for ED medication or to be currently taking such medication than men reporting the fewest concussion symptoms.

Even former players with relatively few concussion symptoms had a heightened risk for low T, suggesting there may be no safe threshold for head trauma. For ED risk, age did not seem to matter.

“We found the same association of concussions with ED among both younger and older men in the study, and we found the same risk of ED among men who had last played twenty years ago,” said senior author Andrea Roberts, a Research Associate in the Department of Social and Behavioral Sciences at the Harvard T.H. Chan School of Public Health. ”These findings suggest that increased risk of ED following head injury may occur at relatively young ages and may linger for decades thereafter.”

The increased ED risk remained even after researchers accounted for other possible causes such as diabetes, heart disease or sleep apnea.

The good news is that ED is easily treatable. And getting it treated is important because ED can signal the presence of other health problems, including heart disease and diabetes. Those are two good reasons to tell your doctor if you suspect you have it.

For more details, see the article in JAMA Neurology, which is freely available.