A low sperm count means there are fewer sperm than expected in a semen sample. It does not mean a man cannot become a father, but it can lower the chance of pregnancy each month, especially if sperm movement or shape is also abnormal. Many men find out only after months of trying to conceive, because low sperm count usually does not cause pain, changes in erections, or obvious semen changes.
The result also needs context. One semen test can be low because of fever, heat exposure, timing, illness, lab variation, or a short-term health issue. Doctors usually repeat the test before making major decisions. The next step is to look for fixable causes, such as varicocele, medication effects, hormone problems, infection, smoking, anabolic steroid use, excess heat, or lifestyle factors. Treatment may involve lifestyle changes, stopping harmful drugs, hormone-based treatment, varicocele repair, or assisted reproduction.
Table of Contents
- What Low Sperm Count Means
- Signs and When to Get Tested
- Common Causes and Risk Factors
- Semen Analysis and Other Tests
- What Results Can and Cannot Predict
- Ways to Improve Sperm Count
- Medical and Fertility Treatment Options
- Timeline and Next Steps
What Low Sperm Count Means
Low sperm count is usually found on a semen analysis, the lab test that checks sperm concentration, total sperm number, movement, shape, semen volume, and other features. The medical term is oligozoospermia. “Oligo” means few, and “zoospermia” refers to sperm in semen.
Sperm count can be described in two related ways:
- Sperm concentration: how many sperm are found in each milliliter of semen.
- Total sperm number: the sperm concentration multiplied by the semen volume.
A man can have a normal concentration but a low total count if semen volume is very low. He can also have a low concentration but still have a reasonable total number if semen volume is higher. That is why the full semen analysis matters more than one number.
Many labs still use a lower reference range around 15 million sperm per milliliter, while newer WHO-based reporting often uses about 16 million sperm per milliliter as a lower reference point. These numbers are not a clean fertility cutoff. Men below them may still conceive naturally, and men above them may still have fertility problems if sperm movement, sperm shape, timing of intercourse, or the female partner’s fertility is also affected.
A low result should be read as a clue, not a final verdict. It points to a lower chance per cycle and a need to look for causes. It does not tell you exactly whether pregnancy will happen, how long it will take, or which treatment will be needed.
A related result is azoospermia, which means no sperm are seen in the semen sample. That is different from a low count and usually needs a more specialized workup. Men with a report showing no sperm should review azoospermia causes and treatment options with a reproductive urologist rather than assuming the same plan applies.
Signs and When to Get Tested
Most men with low sperm count feel normal. Erections, ejaculation, sex drive, and semen appearance can all seem unchanged. The most common “symptom” is not getting pregnant after regular unprotected sex.
Testing is worth considering when:
- Pregnancy has not happened after 12 months of trying.
- Pregnancy has not happened after 6 months and the female partner is 35 or older.
- There is a known male risk factor, such as prior testicular surgery, undescended testicle, chemotherapy, testosterone use, anabolic steroid use, varicocele, or past genital infection.
- There have been repeated miscarriages.
- Semen volume is very low, orgasms feel “dry,” or ejaculation changed after surgery or medication.
- There is testicular pain, swelling, a lump, or a clear size difference between testicles.
A semen analysis is also reasonable before trying for a baby if a man has a strong reason to worry. That may include a history of cancer treatment, long-term testosterone therapy, severe mumps after puberty, pelvic surgery, or a previous infertility diagnosis.
At-home sperm tests can be useful for privacy and convenience, but they do not replace a full lab semen analysis. Many home tests measure only sperm concentration or total count. They may not fully assess motility, morphology, semen volume, white blood cells, or other details that guide treatment. A normal home result can still miss a fertility issue, and an abnormal home result should be confirmed by a laboratory test. For a closer look at what these kits can and cannot show, see at-home sperm test limitations.
Seek prompt medical care rather than waiting for fertility testing if there is sudden severe testicular pain, a new hard lump, fever with scrotal pain, blood in urine, or signs of a sexually transmitted infection such as discharge, burning, sores, or swollen lymph nodes.
Common Causes and Risk Factors
Low sperm count can come from the testicles, hormones, the tubes that carry sperm, sexual function, medications, heat, illness, lifestyle factors, or genetics. Sometimes no single cause is found, even after a careful workup.
Varicocele
A varicocele is enlarged veins in the scrotum, usually more noticeable on the left side. It can raise local temperature and affect sperm production. Some men feel a dull ache or heaviness; others notice nothing.
Not every varicocele needs treatment. Repair is usually considered when it is felt on exam, the couple is having trouble conceiving, and semen results are abnormal. Small varicoceles found only on ultrasound are less likely to explain fertility problems by themselves. A detailed guide to symptoms and treatment is available in varicocele and fertility impact.
Hormone problems
Sperm production depends on signals from the brain and pituitary gland to the testicles. The main hormones doctors look at are FSH, LH, testosterone, and sometimes prolactin and estradiol.
High FSH can suggest the testicles are struggling to produce sperm. Low or low-normal FSH and LH with low testosterone can point toward a signaling problem from the brain or pituitary. Prolactin may be checked when low libido, erectile dysfunction, headaches, breast changes, or very low testosterone are present. For men trying to understand these lab results, LH and FSH testing in men explains the pattern more clearly.
Testosterone therapy and anabolic steroids
Testosterone shots, gels, pellets, and anabolic steroids can sharply lower or stop sperm production. This surprises many men because testosterone may improve energy or libido while reducing fertility.
The body senses the extra testosterone and turns down LH and FSH signaling from the pituitary. Without those signals, the testicles may make much less sperm. In some men, semen analysis drops to azoospermia. Recovery after stopping can take months and may require medical treatment. Men who want children should not start testosterone without discussing fertility preservation or alternatives. A separate guide covers TRT and fertility risks in more detail.
Heat exposure
Sperm production works best when the testicles stay cooler than core body temperature. Repeated heat exposure can lower sperm production in some men, especially when counts are already borderline.
Common sources include frequent hot tubs, saunas, steam rooms, long heated baths, laptops directly on the lap, tight heat-trapping clothing, and some workplace heat exposures. A single sauna visit is unlikely to matter much. Daily or prolonged heat exposure is more concerning when a couple is already struggling to conceive.
Infections and inflammation
Past or current infections can affect sperm count, movement, semen quality, or the tubes that transport sperm. Epididymitis, prostatitis, chlamydia, gonorrhea, mumps after puberty, and some urinary infections can be involved.
Warning signs include pelvic pain, testicular pain, painful ejaculation, burning with urination, penile discharge, fever, or blood in semen. Sometimes inflammation is found because the semen test shows many white blood cells. STI testing is important when there has been possible exposure, new discharge, genital sores, or a partner with symptoms.
Medications and chemicals
Some medications can affect sperm production, ejaculation, hormones, or sexual function. Examples include testosterone, anabolic steroids, some chemotherapy drugs, certain prostate medications, opioids, some antidepressants, spironolactone, ketoconazole, and drugs that affect ejaculation.
Do not stop a prescribed medication on your own. The safer step is to ask the prescribing clinician whether the drug can affect fertility and whether a substitute is possible.
Workplace and environmental exposures may also matter. Pesticides, solvents, heavy metals, radiation, and some industrial chemicals can affect reproductive health. Protective equipment and exposure review become more important when semen results are repeatedly abnormal.
Smoking, cannabis, alcohol, and obesity
Smoking is linked with poorer semen parameters and sperm DNA changes. Vaping and nicotine products are less well studied, but nicotine and other exposures are still concerns. Cannabis may affect hormones, sperm movement, and sperm function in some studies, although results vary.
Heavy alcohol use can affect testosterone, liver function, sleep, and semen quality. Moderate use is less clear, but cutting back is sensible during fertility efforts, especially when a semen test is already abnormal. For a focused discussion, see alcohol and male fertility.
Obesity can affect testosterone, inflammation, sleep apnea risk, insulin resistance, and scrotal heat. Weight loss may improve overall health and sometimes reproductive hormones, but semen improvement is not instant.
Genetic or developmental causes
Some men have low sperm production because of genetic or developmental factors. Examples include undescended testicles, small testicular size, Klinefelter syndrome, Y-chromosome microdeletions, or congenital absence of the vas deferens. These causes are more likely when counts are extremely low, testicles are small, FSH is high, or azoospermia is present.
Genetic testing may be recommended when sperm concentration is very low or no sperm are seen. The reason is not only diagnosis. Some genetic findings affect treatment choices and may have implications for future children.
Semen Analysis and Other Tests
A semen analysis should usually be done after 2 to 7 days without ejaculation, unless the lab gives different instructions. The sample is ideally collected by masturbation into a sterile container and delivered quickly, kept close to body temperature. Lubricants, saliva, incomplete collection, long transport time, and very long abstinence can affect the result.
Because sperm results vary naturally, one low test is not enough for a complete conclusion. If the first test is abnormal, doctors commonly repeat it at least several weeks later, often about a month or more apart. A recent fever, flu, COVID infection, heat exposure, heavy drinking period, or major stress can temporarily lower results.
A full semen analysis may include:
| Measure | What it tells you | Why it matters |
|---|---|---|
| Semen volume | Amount of fluid ejaculated | Low volume can suggest collection issues, dehydration, blockage, retrograde ejaculation, or hormone problems. |
| Sperm concentration | Sperm per milliliter | This is the number most people mean by “sperm count.” |
| Total sperm number | Total sperm in the entire sample | Combines concentration and volume. |
| Motility | How many sperm move and how well they move | Sperm need movement to reach and fertilize an egg. |
| Morphology | Sperm shape under strict lab criteria | Low morphology can matter, but it is often overinterpreted when isolated. |
| pH and round cells | Clues about infection, inflammation, or gland function | May lead to urine, STI, or semen culture testing. |
If the repeat test confirms low sperm count, further testing depends on the pattern. A typical evaluation may include:
- Medical, sexual, medication, and fertility history.
- Physical exam of the testicles, epididymis, vas deferens, penis, and scrotal veins.
- Hormone labs, especially testosterone and FSH when sperm concentration is very low.
- LH, prolactin, estradiol, thyroid testing, or other labs when symptoms suggest them.
- Scrotal ultrasound when the exam is unclear or there is pain, swelling, or concern for a mass.
- Genetic testing when sperm concentration is extremely low or no sperm are present.
- Post-ejaculation urine testing when retrograde ejaculation is suspected.
- STI testing or semen culture when infection is possible.
Sperm DNA fragmentation testing is sometimes used, especially after recurrent pregnancy loss, repeated IVF failure, older paternal age, varicocele, smoking, or unexplained infertility. It is not always the first test, and results should be interpreted by a clinician who understands fertility treatment options. More detail is available in sperm DNA fragmentation and male fertility.
What Results Can and Cannot Predict
A semen analysis estimates fertility potential; it does not predict pregnancy with certainty. Pregnancy depends on the couple, not only the sperm count.
A mildly low sperm concentration with strong motility may still allow natural conception, especially when the female partner is younger, ovulation is regular, tubes are open, and intercourse is timed well. A more severe count problem, poor motility, very low total motile sperm count, or multiple abnormal parameters lowers the chance each month and makes treatment more likely.
The total motile sperm count is often more useful than concentration alone. It estimates how many moving sperm are in the whole sample. This number helps doctors discuss whether timed intercourse, intrauterine insemination, IVF, or IVF with ICSI is more realistic.
Several common mistakes can lead to unnecessary panic:
- Comparing one number to an online chart. The full pattern matters.
- Assuming “low” means sterile. Low count is not the same as no sperm.
- Ignoring the female partner’s age and testing. Both partners should be evaluated in parallel.
- Testing too soon after fever or heat exposure. Sperm production can be temporarily affected.
- Repeating the test at a different lab without context. Lab methods and reference ranges can differ.
- Focusing only on supplements. A varicocele, steroid use, hormone disorder, or obstruction may need specific care.
The result also needs severity. A concentration just below the reference range is handled differently from a count below 5 million per milliliter. Extremely low counts are more likely to need hormone testing, genetic testing, and reproductive urology evaluation.
Semen analysis can also reveal broader health clues. Infertility and abnormal sperm production can be associated with testicular problems, hormone disorders, metabolic health issues, or past medical conditions. That does not mean every man with a low count has a serious disease, but it is one reason not to treat the test as only a fertility number.
Ways to Improve Sperm Count
Sperm take about 2 to 3 months to develop, so changes made today usually show up on a semen analysis several months later. Some causes improve faster, but most fertility plans should be judged over at least one sperm production cycle.
Reduce heat around the testicles
Men with low or borderline counts should avoid repeated high heat during active fertility efforts. This includes hot tubs, saunas, steam rooms, very hot baths, and laptops placed directly on the lap for long periods. Loose, breathable underwear may help comfort and heat control, although underwear choice alone is rarely the whole cause.
Heat changes are most useful when exposure is frequent. Avoiding one occasional sauna session is less important than stopping daily long hot baths or work habits that keep the scrotal area hot for hours.
Stop testosterone and anabolic steroids with medical help
Men using testosterone or anabolic steroids should not try to solve fertility problems with supplements alone. The main issue is hormonal suppression. A reproductive urologist or endocrinologist may use medications such as hCG, clomiphene, enclomiphene, aromatase inhibitors, or FSH-based treatment in selected cases.
Recovery can take months. Men who have used high-dose anabolic steroids, long-term testosterone, or repeated cycles may need closer monitoring.
Quit smoking and reduce cannabis exposure
Stopping smoking is one of the clearest health wins during fertility planning. It may improve sperm parameters, reduce oxidative stress, and improve heart and lung health at the same time. Avoiding secondhand smoke also makes sense.
Cannabis is harder to quantify because products, doses, and patterns vary. Still, men with abnormal semen results are often advised to stop or sharply reduce cannabis while trying to conceive.
Limit alcohol and improve sleep
Heavy drinking can affect hormones, semen quality, liver function, sleep, and sexual function. Cutting down is especially important when alcohol use is frequent, binge-patterned, or paired with poor sleep.
Sleep matters because poor sleep, sleep apnea, shift work, and chronic fatigue can affect testosterone and metabolic health. Loud snoring, morning headaches, high blood pressure, and daytime sleepiness should raise concern for sleep apnea.
Exercise without overtraining
Regular activity supports weight, insulin sensitivity, blood pressure, mood, and testosterone. A mix of cardio and resistance training is usually best.
Extreme endurance training, rapid weight loss, under-eating, or heavy anabolic steroid use can harm reproductive hormones. The goal is not punishing workouts. It is a sustainable routine that improves health without driving the body into chronic stress.
Eat for overall reproductive health
No single “sperm count food” fixes male infertility. A reasonable pattern includes vegetables, fruit, legumes, whole grains, fish or other lean proteins, nuts, olive oil, and enough calories and protein. Highly processed foods, trans fats, and heavy alcohol are worth limiting.
Nutrient deficiencies should be corrected. Vitamin D, zinc, folate, selenium, omega-3 fats, and CoQ10 are often discussed in male fertility, but more is not always better. High-dose supplements can cause side effects or interact with medications.
Be careful with fertility supplements
Antioxidant supplements may improve some semen parameters in some men, but evidence is mixed and pregnancy outcomes are less certain. A supplement may be reasonable when chosen carefully, used for a defined period, and reviewed with a clinician. It should not delay evaluation for severe low count, azoospermia, a varicocele, hormone problems, or the female partner’s age-related fertility concerns.
For men comparing products, male fertility supplement risks and benefits can help separate reasonable options from exaggerated claims.
Medical and Fertility Treatment Options
Treatment depends on the cause, severity, timeline, and the female partner’s fertility. The best plan often combines male evaluation with a parallel reproductive evaluation for the partner.
Treating infection or inflammation
If testing shows an STI, urinary infection, prostatitis, or epididymitis, treatment targets the infection and any partner exposure. Antibiotics are not used just because a sperm count is low. They are used when there is evidence of infection or a strong clinical reason.
Inflammation without clear infection is more complex. A clinician may look for white blood cells in semen, symptoms, urine findings, prostate or epididymal tenderness, and STI risk before deciding on treatment.
Changing medications
When a medication may be affecting sperm production, the prescribing clinician may adjust the dose, switch drugs, or monitor semen results after a change. This is especially important with testosterone, anabolic steroids, some hair-loss or prostate medications, opioids, and drugs that affect ejaculation.
Men should not stop antidepressants, blood pressure drugs, seizure medications, or hormone treatments abruptly. Fertility matters, but so does safety.
Hormone-based treatment
Hormone treatment is most useful when testing shows a treatable pattern. Men with hypogonadotropic hypogonadism may respond to hCG and FSH-based therapy. Some men with low testosterone who want fertility may be candidates for clomiphene, enclomiphene, hCG, or aromatase inhibitors rather than testosterone therapy.
These medications are not one-size-fits-all. They require lab monitoring and time. Semen improvement may take several months, and the goal is sperm production, not simply a higher testosterone number.
Varicocele repair
Varicocele repair may improve semen parameters and pregnancy chances in selected men: those with infertility, abnormal semen results, and a palpable varicocele. Repair is usually not recommended for a tiny varicocele seen only on imaging.
Improvement is not immediate. A semen analysis is often repeated about 3 to 4 months after repair, with some men continuing to improve over 6 months or longer. Repair may help natural conception or improve the odds of less intensive fertility treatment, but it does not guarantee pregnancy.
Intrauterine insemination
Intrauterine insemination, or IUI, places washed sperm directly into the uterus around ovulation. It may be considered when the total motile sperm count is mildly or moderately reduced and the female partner’s evaluation is favorable.
IUI success drops when the post-wash total motile sperm count is very low. In that situation, moving to IVF with ICSI may be more efficient, especially when time matters.
IVF and ICSI
In vitro fertilization, or IVF, involves retrieving eggs and fertilizing them in a lab. ICSI, or intracytoplasmic sperm injection, injects a single sperm into an egg. ICSI is often used for severe male factor infertility because it can work with very low sperm numbers as long as viable sperm are available.
IVF with ICSI does not fix the underlying reason for low sperm count, but it can bypass some sperm-number problems. A male workup is still important because causes such as genetic conditions, hormone disorders, varicocele, or obstruction may affect treatment choices and counseling.
Sperm retrieval
If sperm are extremely low or absent from the ejaculate, sperm may sometimes be retrieved from the testicle or epididymis for use with IVF/ICSI. This is more common in azoospermia but can also be discussed in certain severe cases.
The method depends on whether the problem is blockage or poor sperm production. Microdissection testicular sperm extraction may be used in non-obstructive azoospermia. Epididymal or testicular retrieval may be used when sperm production is normal but transport is blocked.
Sperm banking
Sperm banking is worth discussing before chemotherapy, radiation, testicular surgery, gender-affirming hormone therapy, vasectomy, or treatments that may damage fertility. It can also be useful when sperm count is declining or when treatment timing is uncertain.
Banking several samples gives more flexibility for future IUI, IVF, or ICSI. Even low-count samples may be valuable if ICSI is later needed.
Timeline and Next Steps
The next step after one low result is usually confirmation, not panic. Repeat the semen analysis under good collection conditions, review recent illness or heat exposure, and avoid making major assumptions from one test.
A common timeline looks like this:
- First abnormal test: review collection details, abstinence period, recent fever, medications, heat exposure, and lab comments.
- Repeat test: confirm whether the pattern is persistent. Many clinicians repeat it at least several weeks later.
- Male evaluation: see a reproductive urologist or fertility-focused clinician if results remain abnormal, especially when count is very low.
- Partner evaluation: do not wait months to check ovulation, ovarian reserve, tubes, uterine factors, and age-related issues when pregnancy has not happened.
- Target causes: address varicocele, hormones, infection, medications, heat, smoking, alcohol, weight, sleep, or steroid/testosterone use.
- Recheck after treatment: allow about 3 months for many sperm changes to show, unless the situation calls for faster fertility treatment.
Some situations deserve earlier specialist care:
- Sperm concentration is very low, such as below 5 million per milliliter.
- No sperm are seen.
- Testicles are small or much different in size.
- FSH is high or testosterone is low.
- There is a history of chemotherapy, radiation, undescended testicle, or testicular surgery.
- There is a palpable varicocele with abnormal semen results.
- The female partner is 35 or older.
- There have been recurrent miscarriages or failed fertility treatment cycles.
The emotional side matters too. A low sperm count can trigger shame, blame, or fear, but fertility problems are medical issues, not character flaws. Couples do better when both partners are evaluated and decisions are made from confirmed results rather than assumptions.
A good plan answers four questions: Is the result real? Is there a fixable cause? How much time does the couple have? Which treatment gives the best chance without unnecessary delay? For many men, the answer is not one dramatic intervention. It is a stepwise plan: confirm the result, remove harmful exposures, treat what is treatable, and choose the right fertility option if natural conception remains unlikely.
References
- WHO laboratory manual for the examination and processing of human semen, 6th ed 2021 (Manual)
- Diagnosis and treatment of infertility in men: AUA/ASRM guideline part I 2021 (Guideline)
- Diagnosis and Treatment of Infertility in Men: AUA/ ASRM Guideline Part II 2021 (Guideline)
- Tobacco or marijuana use and infertility: a committee opinion 2024 (Committee Opinion)
- European Association of Urology Guidelines on Male Sexual and Reproductive Health: 2025 Update on Male Infertility 2025 (Guideline)
- Therapeutic efficacy of antioxidant supplementation containing selenium and vitamin E on male infertility: A systematic review and meta-analysis 2026 (Systematic Review)
Disclaimer
This article is for education only and does not replace care from a qualified medical professional. Low sperm count should be confirmed and interpreted with a clinician, especially when results are severe, pregnancy has not happened, hormones are abnormal, or treatment is being considered. Do not stop prescribed medications, testosterone, or fertility-related treatment without medical guidance.
