Most men with fertility problems have no obvious symptoms at all. The only definitive way to confirm male infertility is through a semen analysis, but there are physical signs, lifestyle patterns, and sexual symptoms that can signal a problem before you ever step into a clinic. About half of all couples struggling to conceive have a male factor involved, so knowing what to look for matters.
Physical Signs You Can Notice at Home
A few changes in the body can point toward a fertility issue, even without testing. None of these are guarantees of infertility on their own, but they’re worth paying attention to.
A lump or swelling in the scrotum. Varicoceles, which are enlarged veins in the scrotum, are one of the most common treatable causes of male infertility. A large varicocele can look and feel like a “bag of worms” sitting above the testicle. Smaller ones may only be noticeable by touch. They often cause a dull, aching pain that gets worse after standing for long periods and improves when lying down.
One testicle noticeably smaller than the other. Some size difference between testicles is normal, but a significant discrepancy can indicate damage from a varicocele, an undescended testicle in childhood, or other conditions that reduce sperm production.
Changes in body hair or breast tissue. Low testosterone (hypogonadism) can cause a range of subtle physical shifts. Men may notice they don’t need to shave as often, that facial or body hair is thinning, or that breast tissue has grown. These signs suggest a hormonal imbalance that directly affects sperm production.
Low sex drive. A consistently reduced interest in sex is another hallmark of low testosterone. While plenty of things affect libido, a persistent and unexplained drop, especially combined with other signs on this list, is worth investigating.
Sexual Symptoms That Signal a Problem
What happens during sex can reveal important clues. Difficulty getting or maintaining an erection is sometimes linked to the same hormonal issues that impair fertility. Trouble ejaculating, or pain during ejaculation, can also point to structural or hormonal problems.
One specific condition to be aware of is retrograde ejaculation, where semen travels backward into the bladder instead of out through the penis. The main signs are orgasms that produce very little or no semen (“dry orgasms”) and urine that looks cloudy after sex because it contains semen. Retrograde ejaculation is more common in men with diabetes, spinal cord injuries, or those who’ve had certain prostate or bladder surgeries.
How Semen Analysis Works
A laboratory semen analysis is the gold standard for evaluating male fertility. It measures several factors at once: the total volume of semen, the number and concentration of sperm, the percentage of sperm that are alive (vitality), how well they swim (motility), and whether they’re shaped normally (morphology). Problems with any one of these can reduce fertility.
You’ll typically be asked to abstain from ejaculation for two to five days before the test, then provide a sample at the clinic or at home with a special collection kit. Because sperm counts naturally fluctuate, doctors usually order at least two analyses spaced a few weeks apart before drawing conclusions.
It takes roughly 42 to 76 days for sperm to fully develop and reach maturity. This means a semen analysis reflects conditions from about two to three months earlier. If you’ve recently been sick, stressed, or exposed to unusual heat, your results may not represent your baseline.
Home Sperm Tests: What They Can and Can’t Tell You
At-home sperm tests are widely available and can confirm that sperm are present in your semen. Some newer kits also report basic information about how well sperm move. But most home tests measure only one or two factors linked to fertility.
A lab semen analysis, by comparison, evaluates six or more parameters. A home test won’t tell you about sperm shape, concentration relative to semen volume, or the percentage of living sperm. A “normal” result on a home test can be falsely reassuring, and an “abnormal” one may not capture the full picture. These kits are a reasonable first step if you want a quick screen, but they don’t replace a clinical evaluation.
What Happens at a Fertility Workup
If a semen analysis comes back abnormal, doctors typically dig deeper. Blood tests check hormone levels, particularly testosterone and follicle-stimulating hormone (FSH), which directly regulate sperm production. Abnormal hormone levels can explain why sperm counts are low and help determine whether the problem is in the testicles themselves or in the brain signals that control them.
A scrotal ultrasound is one of the most useful imaging tools. It can detect varicoceles (veins wider than 3 mm are considered abnormal), measure testicular size, identify fluid buildup around the testicle, spot cysts or tumors, and evaluate the epididymis, the coiled tube where sperm mature and are stored. It can also reveal if the vas deferens, the tube that carries sperm out, is absent, a condition sometimes linked to carrying the cystic fibrosis gene.
For men with very low sperm counts, specifically below 1 million sperm per milliliter, genetic testing may be recommended. This looks for small missing segments on the Y chromosome that can impair or completely block sperm production. The results don’t just explain infertility; they also help predict whether procedures like sperm extraction are likely to succeed.
Lifestyle Factors That Affect Sperm Quality
Sperm production is surprisingly sensitive to environment and habits. Heat is one of the best-documented threats. The testicles hang outside the body for a reason: they need to stay a few degrees cooler than core body temperature. Research tracking men over nearly two decades found that exposure to heat waves during the 64 to 90 days before a semen sample was collected led to lower sperm counts and more abnormally shaped sperm. The same principle applies to frequent hot tub use, saunas, laptop computers placed directly on the lap, and prolonged sitting.
Obesity matters too, both because excess body fat converts testosterone into estrogen and because it raises scrotal temperature. Smoking, heavy alcohol use, and anabolic steroids all suppress sperm production. Steroids are particularly damaging because they shut down the body’s own testosterone production, sometimes for months after stopping use.
The good news about lifestyle factors is that sperm are constantly being produced in new cycles. Because the full development window is roughly two to three months, improvements to diet, weight, temperature exposure, or substance use can show up in a semen analysis within that timeframe.
When Infertility Has No Obvious Cause
In roughly 30 to 40 percent of male infertility cases, no clear cause is found. Semen parameters may be abnormal, but hormones, imaging, and genetics all come back normal. This is called idiopathic infertility, and while it’s frustrating, it doesn’t mean nothing can be done. Empiric treatments targeting lifestyle, antioxidant supplementation, or assisted reproduction techniques like intrauterine insemination or in vitro fertilization can still lead to conception. The critical first step is getting the testing done, because you can’t address a problem you haven’t identified.