What is a Low Sperm Count?
According to the WHO, a normal sperm count is 15 million sperm per millilitre or more. Below this is classed as oligospermia (low count); a complete absence of sperm in the ejaculate is called azoospermia. Lower counts reduce — but rarely eliminate — the chance of natural conception, and many men with low counts father children either naturally or with assistance.
Common Causes
Varicocele: enlarged veins in the scrotum, the most common reversible cause
Hormonal imbalances affecting FSH, LH or testosterone
Infections (current or past) that damage sperm production
Genetic conditions such as Klinefelter syndrome or Y-chromosome microdeletions
Medications: anabolic steroids, chemotherapy, some antidepressants
Lifestyle factors: smoking, heavy alcohol use, obesity, heat exposure, stress
Blockages in the reproductive tract preventing sperm release
Retrograde ejaculation, where sperm enter the bladder instead
Diagnosis and Treatment
A repeat semen analysis after 4-6 weeks confirms the result (counts vary day-to-day)
Hormone blood tests (FSH, LH, testosterone, prolactin) help identify causes
A scrotal ultrasound can detect varicocele or blockages
Genetic testing if the count is very low
Lifestyle changes are the first-line approach for mild-to-moderate cases
Medications can correct hormonal causes
Surgery (varicocele repair, blockage removal) helps in selected cases
Assisted reproduction: IUI for milder cases; IVF with ICSI for severe cases — even single sperm can be used