Azoospermia is a condition in which a man’s semen contains no sperm. It is an important cause of male infertility. Azoospermia affects about 1% of all men and 10% to 15% of men with infertility. The condition can be caused by a range of factors including blockages, hormonal problems, or genetic issues. Advances in diagnosis and treatment now offer many men with azoospermia a chance to father biological children.

Azoospermia means there are no sperm present in a man’s semen (ejaculate). This condition is a significant cause of male infertility and can result from problems with sperm production or passage of sperm through the male reproductive system.

Azoospermia can be obstructive or nonobstructive. About 60% of azoospermia cases are nonobstructive; the rest are obstructive.

• In nonobstructive azoospermia, the testes do not produce enough sperm or any sperm at all. This can be due to genetic conditions or hormonal imbalances. It can also result from exposure to toxins, infections like mumps, or side effects from certain medications such as anabolic steroids or chemotherapy. Some men have nonobstructive azoospermia because of problems with the pituitary gland or hypothalamus, which help control hormones involved in sperm production.
• In obstructive azoospermia, a normal amount of sperm is produced in the testes but cannot reach the semen due to a blockage somewhere in the reproductive tract. Causes include infections, scarring from previous injury or surgery, or a condition in which the vas deferens (the tubes that carry sperm) is missing. Vasectomy, an elective surgical procedure to disconnect the vas deferens and prevent pregnancy in a partner, also results in obstructive azoospermia.

Azoospermia can also be classified based on where the problem occurs:

• Pre-testicular azoospermia occurs when hormonal problems interfere with the signals that tell the testes to produce sperm.
• Testicular azoospermia results from problems within the testes themselves.
• Post-testicular azoospermia results from blockages or issues after sperm are made.
• Idiopathic azoospermia is the term used to describe cases of azoospermia in which the exact cause is not known.

Risk factors that may increase the chance of having azoospermia include genetics, medical history, and environmental exposures. The following can raise the risk of azoospermia:

• Certain genetic conditions, including Klinefelter syndrome (in which someone has two X chromosomes and a Y chromosome), Y chromosome microdeletions (in which parts of the Y chromosome are missing), or cystic fibrosis gene mutations, can affect sperm production or cause blockages.
• A history of undescended testes (cryptorchidism) can impair sperm development. Cases where both testicles are affected, where the testicles are found higher up in the abdomen, and where repair is delayed are more likely to affect fertility.
• Previous surgeries on the reproductive tract, such as vasectomy or hernia repair, may cause blockages.
• Infections, including mumps orchitis (inflammation of the testes caused by the mumps virus) or sexually transmitted infections, can damage the testes or ducts.
• Exposure to chemotherapy or radiation therapy can harm sperm-producing cells in the testes.
• Use of anabolic steroids or testosterone supplements can suppress the body’s natural hormone production and reduce sperm counts.
• Hormonal disorders, such as dysfunction of the pituitary gland or hypothalamus, can affect sperm production.
• Varicocele (enlargement of veins in the scrotum) can raise testicular temperature and reduce sperm production.
• Environmental or occupational exposure to toxins, such as pesticides, heavy metals, or industrial chemicals, may damage sperm cells.
• Chronic medical conditions, including diabetes or certain tumors, can interfere with hormone levels or reproductive function.

Azoospermia itself usually does not cause noticeable symptoms. Most men discover the condition when they and their partner have trouble conceiving and seek fertility testing. When azoospermia is associated with a genetic condition, hormonal imbalances, or previous surgery, it is more likely to result in symptoms other than infertility.

Signs and symptoms of azoospermia may include:

• Infertility, or the inability to achieve pregnancy with a partner
• Low semen volume or dry ejaculation due to a blockage or ejaculatory problem
• Swelling, pain, or discomfort in the testicles or scrotum caused by infections, varicocele, or injury
• Small or firm testicles, which may be a sign of a genetic condition or problems with sperm production
• Decreased facial or body hair or breast enlargement, which may be signs of a hormonal imbalance associated with azoospermia

Most men with azoospermia feel healthy and only learn about the condition during an infertility evaluation.

Azoospermia is diagnosed through a combination of medical history, physical examination, and laboratory tests.

The doctor will review medical, surgical, and reproductive history and ask about childhood illnesses, injuries, infections, medication use, or exposure to toxins. Doctors may also ask about family history of genetic conditions and any previous fertility issues.

During the physical examination, the doctor checks testicular size and consistency, looks for the presence of the vas deferens and any abnormalities in the scrotum or penis, and checks for signs of hormonal problems. The doctor may also look for signs of varicocele, breast enlargement, or other features that may suggest hormonal or genetic disorders.

The main test used to diagnose azoospermia is semen testing. Other tests may be used in some cases as part of the evaluation, including:

• Semen analysis checks the level of sperm as well as semen volume and other characteristics. A diagnosis of azoospermia requires at least two separate semen samples, collected at least two weeks apart with a few days of sexual abstinence before each collection.
• Hormone testing measures levels of testosterone, follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin, and sometimes estradiol and thyroid hormones. These tests help determine if the problem is hormonal or related to the testes.
• Genetic testing checks for chromosomal abnormalities such as Klinefelter syndrome, Y chromosome microdeletions, or cystic fibrosis gene mutations, especially in men with nonobstructive azoospermia or an absent vas deferens.
• Scrotal ultrasound uses sound waves to assess testicular size, structure, and blood flow. This test can help detect varicoceles, cysts, or other abnormalities, though varicoceles are most often diagnosed through physical examination.
• Transrectal ultrasound examines the prostate and seminal vesicles to look for blockages or structural problems in the reproductive tract.
• Testicular biopsy involves removing a small sample of testicular tissue to check for sperm production and to help distinguish between obstructive and nonobstructive causes. This procedure is usually done if other tests do not provide a clear diagnosis.
• Post-ejaculation urine analysis checks for sperm in the urine, which can indicate retrograde ejaculation (when semen flows backward into the bladder).

Treatment for azoospermia depends on the underlying cause, whether sperm production is possible, and the person’s or couple’s reproductive goals. If pregnancy is not desired, no treatment may be necessary unless azoospermia is caused by a medical condition that has other negative effects on health.

Treatments for azoospermia focus on increasing sperm count, repairing or bypassing the blockage, or retrieving sperm in another way.

Treatments to increase sperm count or address blockages include:

• Surgery: Procedures such as vasovasostomy (to reconnect the vas deferens) or vasoepididymostomy (connecting the vas deferens to the epididymis) can restore the flow of sperm in some cases, including after elective vasectomy or injury. Surgery to correct varicocele may improve sperm production in selected men, although the benefit is not guaranteed.
• Hormonal therapy: For men with hypogonadotropic hypogonadism or other hormonal causes of azoospermia, medications like human chorionic gonadotropin (HCG), follicle-stimulating hormone (FSH), or gonadotropin-releasing hormone (GnRH) may stimulate sperm production. Hormonal therapy can take several months to show results.
• Stopping harmful medications or exposures: If azoospermia is caused by anabolic steroids, testosterone supplements, or exposure to toxins, stopping these agents may allow sperm production to recover over time.
• Treatment of underlying medical conditions: Managing chronic illnesses, infections, or hormonal disorders may improve fertility in some men.
• Genetic counseling: Men with genetic causes of azoospermia should receive counseling about the risks of passing genetic conditions to their children and may be offered pre-implantation genetic testing if using assisted reproduction.

If surgery to address a blockage is not possible or is unsuccessful, or if other treatments do not raise sperm counts enough, sperm retrieval techniques combined with other assisted reproductive technologies (ART) can result in a pregnancy without directly treating azoospermia. In obstructive azoospermia, sperm may be collected directly from the testes or epididymis using procedures like testicular sperm extraction (TESE), testicular sperm aspiration (TESA), or microsurgical epididymal sperm aspiration (MESA). In nonobstructive azoospermia, small amounts of sperm are found in about 40% of patients through microsurgical testicular sperm extraction (micro-TESE).

Retrieved sperm can then be used in assisted reproductive technologies. For example, in vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI) may be used when sperm are retrieved in very low numbers. ICSI involves injecting a single sperm directly into an egg to achieve fertilization. If no sperm can be retrieved or produced, couples may consider using donor sperm for insemination or pursuing adoption.

The choice of treatment depends on the specific diagnosis, the couple’s preferences, and the likelihood of success with each option.

Azoospermia can lead to several complications affecting physical, emotional, and social well-being. The main complications of azoospermia include:

• Emotional and psychological effects: Azoospermia causes infertility, which can cause distress for individuals and couples hoping to have children. Undergoing infertility treatments can cause anxiety, depression, or relationship strain.
• Increased risk of certain health conditions, such as testicular cancer or hormonal imbalances, especially in men with genetic causes of azoospermia.
• Transmission of genetic abnormalities to offspring if assisted reproductive technologies are used without proper genetic counseling and testing.

In addition, treatments for azoospermia can lead to other complications, including:

• Risk of bleeding (hematoma), infection, or scarring (fibrosis) of the testis as a result of surgical procedures.
• Testicular atrophy, or shrinkage of the testicles, may occur after certain treatments or as a result of underlying disease.
• Financial and emotional stress from pursuing fertility treatments, which can be costly and time-consuming.

If a man with azoospermia experiences sudden pain, swelling, or signs of infection, especially after a procedure, he should contact his healthcare provider promptly.

The outlook for men with azoospermia depends on the cause and treatment availability, as well as the reproductive goals of the man or couple. Many men with obstructive azoospermia can achieve biological fatherhood through surgery or assisted reproductive techniques.

For those with nonobstructive azoospermia, success rates are lower but improving, as advanced sperm retrieval and IVF methods can sometimes find and use small numbers of sperm. In some cases, no sperm can be found, and alternative options such as use of donor sperm or adoption may be considered. Early diagnosis, individualized treatment, and emotional support can help men and couples navigate the challenges of azoospermia and improve their chances of building a family.

This article was medically reviewed in July 2026.