Male infertility is more common than most people realize. A male factor is the sole or contributing cause in roughly 40% to 60% of all couples who struggle to conceive, with male-only factors accounting for 20% to 30% of cases. The standard clinical threshold is straightforward: if you and your partner have been having regular, unprotected sex for 12 months without a pregnancy (or 6 months if your partner is 35 or older), it’s time for a fertility evaluation. But there are also physical signs, lifestyle factors, and simple tests that can give you earlier clues.
Physical Signs Worth Paying Attention To
Some men have no symptoms at all and only discover a fertility issue after testing. Others have noticeable signs that something may be off. A varicocele, which is an enlarged vein in the scrotum, is one of the most common physical findings in infertile men. You might feel a small lump above the testicle, notice swelling, or in more obvious cases feel something described as a “bag of worms” in the scrotum. Larger varicoceles can lower testosterone, which in turn may shrink the testicles, reduce sex drive, decrease muscle mass, and contribute to depression.
Testicle size itself matters. Noticeably small or soft testicles can indicate reduced sperm production. Pain or swelling in the testicles, whether constant or recurring, is another signal worth investigating. On the hormonal side, breast tissue growth (gynecomastia), loss of body or facial hair, and persistent low energy or mood changes can all point to hormonal imbalances that affect fertility.
Ejaculation issues are another category. If you consistently produce very little or no semen during orgasm, or if your urine looks cloudy afterward, you may have retrograde ejaculation, a condition where semen travels backward into the bladder instead of out through the penis. This is diagnosed with a simple urine test taken shortly after ejaculation, which will show sperm in the urine.
Lifestyle Factors That Hurt Sperm Quality
Your daily habits have a surprisingly large impact on fertility. A cross-sectional study examining sperm health found that obesity was the single strongest predictor of abnormal sperm concentration and motility. Obese men were roughly 40 times more likely to have abnormal sperm concentration and 13 times more likely to have abnormal sperm motility compared to men at a healthy weight. Those numbers are striking, and they suggest that weight is not a minor variable in the fertility equation.
Smoking is similarly damaging. Moderate to heavy smokers were about 17 times more likely to have abnormal sperm concentration and nearly 6 times more likely to have poor sperm motility. Heavy alcohol use, anabolic steroid use, chronic heat exposure to the testicles (from hot tubs, saunas, or laptops on the lap), and certain medications can also suppress sperm production. If any of these apply to you, addressing them is one of the most direct things you can do before or alongside medical testing.
The Semen Analysis: What It Measures
A semen analysis is the cornerstone test for male fertility. You provide a sample, typically after 2 to 5 days of abstinence, and a lab evaluates it across several dimensions. The key numbers come from the World Health Organization’s reference values, which define the lower limits of normal:
- Sperm concentration: at least 16 million sperm per milliliter
- Total motility: at least 42% of sperm moving, with 30% or more showing forward (progressive) movement
- Normal morphology: at least 4% of sperm with a normal shape
Falling below any of these thresholds doesn’t automatically mean you can’t conceive, but it does mean your odds are reduced and further investigation is warranted. Because sperm production takes about 72 days and can fluctuate, doctors often repeat an abnormal semen analysis after a few weeks to confirm the results.
At-Home Sperm Tests: Useful but Limited
Home testing kits are widely available and can measure sperm count, semen volume, and sometimes pH. They’re not inaccurate for what they measure, but they leave out critical information. A home test might tell you that you have 100 million sperm, but it can’t tell you whether any of them are actually moving. Only a laboratory analysis, where semen is evaluated under a microscope and by computer, can assess motility, vitality (the percentage of sperm that are alive), and morphology in detail.
Think of a home test as a screening tool. A normal result is somewhat reassuring but not definitive. An abnormal result is a clear signal to get a full lab analysis. If you’re serious about understanding your fertility, the clinical semen analysis is the test that matters.
Hormone Testing and Blood Work
If a semen analysis comes back abnormal, the next step is usually blood work. Doctors check testosterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) to understand whether the brain is sending the right signals to the testicles and whether the testicles are responding. Low testosterone with high FSH, for example, suggests the testicles themselves are underperforming. Low levels across the board may point to a problem with the pituitary gland. Thyroid hormones and prolactin levels are sometimes checked as well, since abnormalities in either can suppress sperm production.
When Genetic Testing Comes Into Play
For men with very low sperm counts, genetic testing becomes important. Researchers have found that Y-chromosome deletions, which are missing segments of genetic material on the male sex chromosome, appear in about 6.8% of men with no detectable sperm (azoospermia) and about 1% of men with concentrations under 1 million per milliliter. These deletions can be inherited by sons conceived through assisted reproduction, so identifying them matters for both diagnosis and family planning. Genetic screening is typically recommended when sperm concentration falls below 5 million per milliliter, though some experts argue the threshold should be closer to 1 million to better target men who are most likely to carry these deletions.
Karyotype testing, which looks at the full set of chromosomes, may also be ordered. Conditions like Klinefelter syndrome (where a man carries an extra X chromosome) are a well-known genetic cause of infertility and are often discovered only during a fertility workup.
Other Diagnostic Steps
Depending on initial findings, additional tests may include a scrotal ultrasound to check for varicoceles or structural abnormalities, a transrectal ultrasound to look for blockages in the reproductive tract, and a post-ejaculatory urine test if retrograde ejaculation is suspected. In rare cases where blood work and imaging don’t explain a very low sperm count, a testicular biopsy can determine whether the testicles are producing sperm that simply aren’t making it into the ejaculate due to a blockage.
What You Can Do Right Now
If you’re wondering about your fertility but aren’t yet at the 6- or 12-month mark of trying, there are practical steps you can take. Losing weight if your BMI is elevated, quitting smoking, cutting back on alcohol, and avoiding prolonged heat exposure to the groin are all changes supported by evidence. These won’t guarantee normal fertility, but they remove some of the most significant modifiable risk factors.
If you’ve noticed any of the physical signs described above, or if you already know you have a condition like diabetes or a history of undescended testicles, those are reasons to get tested sooner rather than waiting a full year. A semen analysis is inexpensive, noninvasive, and gives you concrete information. For many men, the hardest part is simply making the appointment.