For men, the infertility problems that can be brought on by poor semen quality can be a frustrating obstacle to starting a family. They may also be a sign of more widespread health problems, according to a recent study.

Semen is the fluid in which sperm are found. Though sperm get star billing, they only make up 2 to 5% of the semen's volume.

Looking at the medical records of over 9,000 men with fertility problems, the study compared the overall health status of men who had semen defects (about half) to those whose fertility problems stemmed from some other cause.

Though sperm get star billing, they only make up 2 to 5% of the semen's volume.

In what the researchers describe as a “substantial link,” men with abnormal semen were considerably more likely to also have high blood pressure, vascular disease or heart disease. They also found that the more different defects a man's semen had, the more likely he was to also have an endocrine disorder or a skin disease.

Particularly troubling was that the average age of the men was 38. Heart and vascular disease, as well as high blood pressure, are more commonly found in older men.

Fully 44% had some other health problem in addition to the fertility problem that brought them into the clinic.

The new findings further support another study by the same lab published earlier this year, which found that men with semen problems had a higher risk of death in the eight years following a fertility evaluation than men with normal semen.

The semen problems that were associated with a higher risk of death included defects in semen volume, sperm concentration, sperm motility and sperm count. Simply having sperm with an abnormal structure or shape did not increase this risk.

Taken together, the two studies suggest that problems with semen indicate that a man may also have more general health problems and may be a warning that a checkup is needed.

“As we treat men’s infertility, we should also assess their overall health. That visit to a fertility clinic represents a big opportunity to improve their treatment for other conditions, which we now suspect could actually help resolve the infertility they came in for in the first place,” said Michael Eisenberg, an assistant professor of urology and director of male reproductive medicine and surgery at Stanford University School of Medicine and lead author of both studies.

An article on the latest study appears in Fertility and Sterility.