Male Infertility: Signs, Symptoms, Causes and Treatment

Quick Answer

Male infertility is when a problem with a man's sperm or reproductive system makes it difficult to father a child. It is common, contributing to around 40 to 50 percent of all fertility problems in couples, so it is never a "woman's issue" alone. The most frequent causes are low sperm count or quality, varicocele (swollen veins in the scrotum), and hormonal problems. Often there are no obvious symptoms except difficulty conceiving. The key test is a simple semen analysis, and many causes are treatable.

Key Takeaways

• Male factors contribute to nearly half of couples' infertility, so both partners should be assessed when conceiving is difficult (Cleveland Clinic).

• Often there are no symptoms other than being unable to conceive. When symptoms occur, they may involve ejaculation, libido, or a swelling or lump in the testicle.

• Common causes include low sperm count (oligospermia), poor sperm movement or shape, varicocele, hormonal problems and blockages.

• A semen analysis is the main test, and it is simple, painless and widely available.

• Many causes are treatable, through lifestyle changes, medicines, surgery (such as varicocele repair) or assisted reproduction like IVF and ICSI. Getting assessed early helps.

What Is Male Infertility?

Male infertility means a health problem in a man reduces the chance of his partner becoming pregnant. For a pregnancy to happen naturally, a man needs to produce enough healthy sperm, the sperm must move well, and they must be able to reach and fertilise the egg. A problem at any of these stages can cause infertility.

It is far more common than many people realise. Male factors contribute to roughly 40 to 50 percent of infertility cases in couples, with a male factor being the main cause in about a third (Cleveland Clinic; NICE, UK). In couples struggling to conceive, roughly a third of problems are mainly male, a third mainly female, about a fifth involve both partners, and around one in ten remain unexplained. This is exactly why both partners should be checked when conceiving is difficult, rather than assuming it is one person's issue.

What Are the Signs and Symptoms of Male Infertility?

The most important thing to understand is that male infertility often has no obvious symptoms at all. Many men feel completely well, and the only sign is that a pregnancy is not happening despite regular, unprotected sex.

When symptoms do occur, they can include (Cleveland Clinic):

• Difficulty conceiving after a year of trying (or six months if the female partner is 35 or older)

• Problems with ejaculation, such as very little fluid, or ejaculation going backward into the bladder

• Reduced sexual desire (low libido) or erection difficulties

• Pain, swelling, or a lump in the testicle area

• Reduced facial or body hair, which can hint at a hormonal problem

• Runny or watery semen, which can sometimes reflect a low sperm count

Because symptoms are often absent, the only way to know is through testing, which is straightforward.

What Causes Male Infertility?

There are several causes, and often more than one plays a part. Here are the most common.

1. Sperm problems

The most frequent cause overall. Sperm problems include (Cleveland Clinic, Oligospermia):

• Low sperm count (oligospermia): fewer sperm than normal, generally defined as under 15 million sperm per millilitre of semen. A low count makes conception harder but not always impossible.

• Poor sperm movement (motility): sperm that do not swim well struggle to reach the egg.

• Abnormal sperm shape (morphology): oddly shaped sperm may not fertilise the egg effectively.

• No sperm in the semen (azoospermia): the most severe form, affecting about 1 percent of all men and 10 to 15 percent of infertile men (StatPearls, NIH). It can be due to a blockage (obstructive) or a production problem (non-obstructive).

2. Varicocele

A varicocele is a swelling of the veins that drain the testicle, a bit like a varicose vein in the scrotum. It is one of the most common and, importantly, one of the most correctable causes of male infertility, and it can lower both sperm count and quality by raising the temperature around the testicles (Cleveland Clinic).

3. Hormonal problems

Sperm production depends on hormones from the brain (FSH and LH) and the testicles (testosterone). Low or imbalanced hormones, a condition called hypogonadism, are a frequent identified cause of male infertility and can reduce sperm production (StatPearls). This is why a hormone blood test is often part of the work-up.

4. Blockages (obstruction)

Sperm are made in the testicles and travel through tubes to mix with semen. A blockage anywhere along these tubes, from infection, injury or surgery, can stop sperm reaching the semen, even when production is normal.

5. Ejaculation problems

Retrograde ejaculation, where semen goes backward into the bladder instead of out, and other ejaculation difficulties can prevent sperm from reaching the partner. These can result from surgery, diabetes or certain medicines.

6. Immune causes

Sometimes the body makes antisperm antibodies that mistakenly attack the sperm, affecting their ability to move and fertilise.

7. Other causes

• Genetic conditions (such as Klinefelter syndrome or Y-chromosome problems)

• Undescended testicles in childhood

• Infections, including some sexually transmitted infections and mumps affecting the testicles

• Certain medicines, chemotherapy or radiotherapy

• Tumours affecting the reproductive organs or hormone glands

8. Lifestyle and environmental factors

• Smoking, alcohol and recreational drugs

• Anabolic steroids (used for bodybuilding), which strongly suppress sperm production

• Being significantly overweight

• Excess heat to the testicles, from hot tubs, saunas, very tight clothing or resting a laptop on the lap for long periods

• High stress and poor sleep

• Exposure to certain chemicals, pesticides or toxins

How Is Male Infertility Diagnosed?

The good news is that testing is simple and painless. It usually includes (Cleveland Clinic):

• Semen analysis: the single most important test. A semen sample is examined for the number, movement and shape of sperm. It is often repeated to confirm the result, as sperm counts can vary.

• Hormone blood tests: checking FSH, LH, testosterone and prolactin, since these drive sperm production.

• Physical examination: to check for a varicocele, blockages or other issues.

• Scrotal or transrectal ultrasound: to look at the testicles, veins and tubes.

• Genetic tests: in some cases, especially with very low or absent sperm.

• Other specialised tests, depending on the findings.

A full couple assessment looks at both partners together, which is the right approach.

How Is Male Infertility Treated?

Many causes of male infertility are treatable, and the approach depends on the cause. Broadly (Cleveland Clinic):

• Lifestyle changes: stopping smoking, alcohol and steroids, losing excess weight, avoiding testicular heat, and managing stress can genuinely improve sperm health. See Mylo's guide on foods to increase sperm count.

• Treating the underlying cause: medicines for hormonal problems, antibiotics for infections, or changing a medicine that is affecting fertility.

• Surgery: repairing a varicocele can improve sperm quality in a significant proportion of men, and surgery can also correct some blockages.

• Assisted reproduction (ART): when natural conception is unlikely, treatments such as IUI, IVF, and ICSI (intracytoplasmic sperm injection, where a single sperm is injected into an egg) can help. ICSI is especially useful for severe male-factor infertility. Even in men with no sperm in the semen, sperm can sometimes be retrieved surgically from the testicle for use in IVF or ICSI.

For a fuller overview, see Mylo's guide to male infertility treatment options.

Can Male Infertility Be Prevented?

Not every cause can be prevented, but you can protect your fertility:

• Do not smoke, and limit alcohol. Avoid recreational drugs and never use anabolic steroids.

• Keep a healthy weight and stay active.

• Avoid excess heat to the testicles (long hot baths, saunas, very tight underwear, laptops on the lap for hours).

• Manage stress and sleep well.

• Treat infections promptly, and practise safe sex to avoid STIs.

• Protect against toxins at work, using recommended safety measures.

• See a doctor early if you have testicular pain, swelling or a lump, or trouble conceiving.

Male Infertility: Frequently Asked Questions

"How common is male infertility?"
Very common. Male factors contribute to around 40 to 50 percent of couples' fertility problems, and are the main cause in about a third of cases. This is why both partners should always be assessed when conceiving is difficult.

"What are the signs of male infertility?"
Often there are none except difficulty conceiving. When present, signs can include ejaculation problems, low sex drive, erection difficulties, or pain, swelling or a lump in the testicles. The only reliable way to know is a semen analysis.

"What is a low sperm count?"
It is generally defined as fewer than 15 million sperm per millilitre of semen, known as oligospermia. A low count makes conception harder but does not always mean a man cannot father a child.

"Can male infertility be cured or treated?"
Many causes can be treated. Options range from lifestyle changes and medicines to surgery (such as varicocele repair) and assisted reproduction like IVF and ICSI. Even when sperm are absent from the semen, they can sometimes be retrieved surgically. Early assessment gives the best chance.

"What is a varicocele, and does it affect fertility?"
A varicocele is a swelling of the veins in the scrotum. It is one of the most common and correctable causes of male infertility, and repairing it can improve sperm quality in many men.

"How is male infertility tested?"
The main test is a simple, painless semen analysis. Your doctor may also do hormone blood tests, a physical examination, an ultrasound and, in some cases, genetic tests.

"Does lifestyle really affect sperm?"
Yes. Smoking, alcohol, anabolic steroids, obesity, excess heat, stress and poor sleep can all reduce sperm health, and improving these can genuinely help. It usually takes a few months for changes to show, as sperm take time to develop.

When To See a Doctor

See a doctor or fertility specialist if you:

• Have been trying to conceive for a year without success (or six months if your partner is 35 or older)

• Have pain, swelling or a lump in the testicles

• Have problems with erections or ejaculation, or low sex drive

• Have had testicular surgery, injury, infections or undescended testicles in the past

Both partners should be assessed together, since the cause can lie with either or both.

This article is for information only and does not replace advice from a doctor or fertility specialist, who can assess and treat your specific situation.

Bottom Line

Male infertility is common, contributing to nearly half of couples' fertility problems, and it is not something to feel ashamed of or to overlook. It often causes no symptoms beyond difficulty conceiving, which is why a simple semen analysis matters so much. The usual causes, low sperm count or quality, varicocele and hormonal problems, are frequently treatable, whether through lifestyle changes, medicines, surgery or assisted reproduction like IVF and ICSI. If you and your partner have been trying without success, see a doctor together and get assessed early, because in many cases there is a clear cause and an effective path forward.

References

All links verified live on 17 September 2026.

1. Male Infertility: Causes, Symptoms, Tests and Treatment — Cleveland Clinic. Source for the definition, that male factors contribute to a large share of infertility, symptoms, causes (sperm problems, varicocele, hormones, obstruction, ejaculation), diagnosis (semen analysis, hormones, ultrasound) and treatment.

2. Male Infertility — StatPearls, National Institutes of Health. Source for azoospermia prevalence, hypogonadism as a common cause, and the clinical approach.

3. Oligospermia (Low Sperm Count) — Cleveland Clinic. Source for the definition of low sperm count (under 15 million per millilitre).

4. Fertility problems: assessment and treatment — National Institute for Health and Care Excellence (NICE), UK. Source for the proportion of infertility due to male factors.

5. Mylo internal guides: what is infertility, FSH, LH, prolactin test, foods to increase sperm count, and male infertility treatment options.