Symptoms

The main sign of low sperm count is the inability to conceive a child. There might be no other obvious signs or symptoms. In some men, an underlying problem such as an inherited chromosomal abnormality, a hormonal imbalance, dilated testicular veins or a condition that blocks the passage of sperm may cause signs and symptoms.

Low sperm count symptoms might include:

• Problems with sexual function — for example, low sex drive or difficulty maintaining an erection (erectile dysfunction)
• Pain, swelling or a lump in the testicle area
• Decreased facial or body hair or other signs of a chromosome or hormone abnormality

Causes

The production of sperm is a complex process and requires normal functioning of the testicles (testes) as well as the hypothalamus and pituitary glands — organs in your brain that produce hormones that trigger sperm production. Once sperm are produced in the testicles, delicate tubes transport them until they mix with semen and are ejaculated out of the penis. Problems with any of these systems can affect sperm production.

Also, there can be problems of abnormal sperm shape (morphology), movement (motility) or function.

However, often the cause of low sperm count isn't identified.

Medical causes:

Low sperm count can be caused by a number of health issues and medical treatments. Some of these include:

• Ejaculation problems : Retrograde ejaculation occurs when semen enters the bladder during orgasm instead of emerging out of the tip of the penis. Various health conditions can cause retrograde ejaculation or lack of ejaculation, including diabetes, spinal injuries, and surgery of the bladder, prostate or urethra. Certain medications also might result in ejaculatory problems, such as blood pressure medications known as alpha blockers. Some ejaculatory problems can be reversed, while others are permanent. In most cases of permanent ejaculation problems, sperm can still be retrieved directly from the testicles.
• Hormone imbalances : The hypothalamus, pituitary and testicles produce hormones that are necessary to create sperm. Alterations in these hormones, as well as from other systems such as the thyroid and adrenal gland, may impair sperm production.
• Certain medications : Testosterone replacement therapy, long-term anabolic steroid use, cancer medications (chemotherapy), certain antifungal and antibiotic medications, some ulcer medications, and other medications can impair sperm production and decrease male fertility.
• Varicocele : A varicocele (VAR-ih-koe-seel) is a swelling of the veins that drain the testicle. It's the most common reversible cause of male infertility. Although the exact reason that varicoceles cause infertility is unknown, it might be related to abnormal testicular temperature regulation. Varicoceles result in reduced quality of the sperm.
• Infection : Some infections can interfere with sperm production or sperm health or can cause scarring that blocks the passage of sperm. These include inflammation of the epididymis (epididymitis) or testicles (orchitis) and some sexually transmitted infections, including gonorrhea or HIV. Although some infections can result in permanent testicular damage, most often sperm can still be retrieved.
• Antibodies that attack sperm : Anti-sperm antibodies are immune system cells that mistakenly identify sperm as harmful invaders and attempt to destroy them.
• Tumors : Cancers and nonmalignant tumors can affect the male reproductive organs directly, through the glands that release hormones related to reproduction, such as the pituitary gland, or through unknown causes. Surgery, radiation or chemotherapy to treat tumors also can affect male fertility.
• Undescended testicles : During fetal development one or both testicles sometimes fail to descend from the abdomen into the sac that normally contains the testicles (scrotum). Decreased fertility is more likely in men with this condition.
• Prior surgeries : Certain surgeries might prevent you from having sperm in your ejaculate, including vasectomy, inguinal hernia repairs, scrotal or testicular surgeries, prostate surgeries, and large abdominal surgeries performed for testicular and rectal cancers, among others. In most cases, surgery can be performed to either reverse these blockages or to retrieve sperm directly from the epididymis and testicles.