There’s no single symptom that confirms male infertility. Most men with fertility problems have no obvious signs at all, and the only reliable way to know is through testing, starting with a semen analysis. That said, certain physical changes, sexual function issues, and lifestyle factors can point toward a problem worth investigating. Doctors generally recommend evaluation after 12 months of regular unprotected intercourse without pregnancy, or after 6 months if the female partner is 35 or older.
Physical Signs You Can Check
A few physical changes are worth paying attention to, though most fertile and infertile men look exactly the same from the outside.
A varicocele, which is an enlarged vein in the scrotum, is one of the most common treatable causes of male infertility. A large varicocele looks and feels like a “bag of worms” above the testicle. Smaller ones aren’t visible but can be felt, especially when standing or bearing down. The affected testicle may also be noticeably smaller than the other one. Varicoceles can cause gradual shrinkage of testicular tissue over time, which affects both sperm production and hormone levels.
Testicular size matters. Smaller-than-average testicles can signal reduced sperm production. Breast tissue growth in men (gynecomastia) may indicate a hormonal imbalance that could affect fertility. Pain, swelling, or lumps in the testicles are worth getting checked regardless of fertility concerns.
Sexual Function Problems as Clues
Sexual dysfunction shows up at surprisingly high rates in men with fertility issues. Erectile dysfunction is present in 18% to 89% of infertile men, a significantly higher prevalence than in fertile men. Some of this is organic, meaning there’s a physical cause like poor blood flow. But a large portion is psychogenic, meaning it develops or worsens specifically during conception attempts. About 21% of men actively trying to conceive report high levels of sexual infertility stress, including loss of enjoyment during sex, pressure around scheduling intercourse, and reduced sexual self-esteem.
Low libido is another signal. Roughly 43% of men presenting to infertility clinics report symptoms consistent with low testosterone, even when their sperm counts look normal. Among men with low sperm counts, 42% to 50% have measurably low testosterone. If your sex drive has dropped noticeably, it’s worth checking hormone levels.
Ejaculation issues also matter. Retrograde ejaculation, where semen travels backward into the bladder instead of out through the penis, produces little or no fluid at climax. The primary sign is a “dry orgasm.” Another clue: cloudy urine after orgasm, caused by sperm mixing into the urine. This condition is diagnosed by checking a urine sample for sperm after ejaculation.
What a Semen Analysis Tells You
A semen analysis is the cornerstone test for male fertility. It measures sperm concentration (how many sperm per milliliter), total sperm count, motility (how well they swim), and morphology (their shape). Interestingly, the most recent WHO guidelines have moved away from strict “normal” vs. “abnormal” cutoffs, recognizing that semen parameters exist on a spectrum rather than a clean pass/fail line. A man with lower numbers may still conceive naturally, while a man with seemingly normal results may still struggle.
That said, very low numbers or the complete absence of sperm (azoospermia) clearly indicate a problem. The test requires providing a sample, typically at a clinic or lab, after 2 to 5 days of abstinence. Because sperm counts fluctuate, doctors often repeat the test at least once before drawing conclusions.
Home Sperm Tests: What They Can and Can’t Do
Several FDA-cleared home sperm tests are now available. Smartphone-based devices like the YO Home Sperm Test measure motile sperm concentration, meaning sperm that are both present and moving. In clinical comparisons, the YO device showed 97.8% accuracy against lab-grade analyzers, with strong correlation for samples up to about 94 million sperm per milliliter. It can reliably flag samples with abnormally low motile sperm concentration below 6 million per milliliter.
Other home tests like SpermCheck and Trak only measure sperm concentration, which is just one of the three key parameters for assessing sperm quality. None of these home kits evaluate morphology, and none can replace a full clinical semen analysis. They’re useful as a screening step. If a home test shows low results, get a proper lab analysis. If it shows normal results but you’ve been trying for a year without success, get tested anyway.
Hormone Testing
Blood tests for reproductive hormones can reveal why sperm production is low. Two hormones from the pituitary gland are particularly important: FSH and LH. FSH directly signals the testicles to produce sperm. If FSH is low, the testicles aren’t getting the message to make sperm. If FSH is high, the testicles are getting the signal but can’t respond properly, which points to a problem within the testicles themselves.
LH works similarly but for testosterone production. High LH with low testosterone means the testicles aren’t functioning well. Low LH means the pituitary gland isn’t doing its job, which is a different problem but one that often responds to treatment.
One critical warning: if you’re using testosterone replacement therapy (gels, injections, patches), it can severely suppress or completely shut down sperm production. Externally supplied testosterone tells the brain to stop sending signals to the testicles, and sperm production drops, sometimes to zero. This is one of the most common medically caused fertility problems, and it’s often reversible once testosterone therapy is stopped.
Genetic Causes
About 1 in 2,000 to 1 in 3,000 men have Y chromosome infertility, caused by missing segments of genes needed for sperm development. These deletions account for roughly 13% of cases where no sperm are produced and about 5% of cases with severely low sperm counts. Genetic testing is typically recommended when sperm counts are very low or absent without another clear explanation.
Other chromosomal conditions, like Klinefelter syndrome (where a man carries an extra X chromosome), can also impair fertility. Genetic screening helps determine whether assisted reproduction is likely to work and whether the condition could be passed to children.
Lifestyle and Environmental Factors
Heat is one of the most well-established environmental threats to sperm. The CDC notes that excess heat exposure can affect male fertility and overall reproductive health. The testicles hang outside the body for a reason: sperm production requires temperatures slightly below core body temperature. Frequent hot tub use, laptop placement directly on the lap, prolonged sitting, and occupational heat exposure (welding, baking, long-haul driving) can all raise scrotal temperature enough to impair sperm quality over time.
Other modifiable risk factors include smoking, heavy alcohol use, obesity, anabolic steroid use, and certain medications. When these factors are present, advanced testing like sperm DNA fragmentation analysis can help determine whether lifestyle changes might improve fertility potential. DNA fragmentation testing is also recommended for couples with unexplained infertility, recurrent pregnancy loss, or repeated failure of fertility treatments like IUI or IVF.
When to Get Tested
The standard recommendation is to seek evaluation after 12 months of regular unprotected sex without conception, or 6 months if the female partner is 35 or older. But if you notice any of the signs described above, there’s no reason to wait. A semen analysis is inexpensive, noninvasive, and provides more information than any symptom checklist. Many men avoid testing because they assume the problem must be on the female side, but male factors contribute to roughly half of all infertility cases. Getting tested early saves time and opens up options sooner.