Couples who have had sex for more than 1 year after marriage without any contraceptive measures and have not impregnated their spouse because of male factors are called male infertility. Common causes are: 1. Sexual dysfunction: erectile dysfunction, premature ejaculation, non-ejaculation, retrograde ejaculation, orgasm disorder, low or lost libido, etc. 2. Varicocele: Varicocele with abnormal semen parameters (palpable or subclinical). 3. Testicular injury: testicular torsion, testicular trauma, etc. 4. Genetic and congenital anomalies: azoospermia with cryptorchidism or incomplete testicular descent, chromosomal abnormalities (e.g., Creutzfeldt-Jakob syndrome, Kalman syndrome), congenital vas deficiency or other congenital disorders. 5. Endocrine abnormalities: hypogonadism, male hyperprolactinemia, abnormal thyroid function, etc. 6. Infectious infertility of male reproductive system: orchitis, prostatitis, vesiculitis, epididymitis, urethritis and sexually transmitted diseases, etc. 7. Immunological factors: anti-sperm antibodies, etc. 8. Sperm transport disorders: azoospermia or oligospermia caused by partial or complete obstruction of the vas deferens, such as vasectomy, trauma, etc. 9. Medical factors: Infertility caused by drugs, medical radiation and surgical factors. 10. Physico-chemical, environmental and occupational factors: radiation, high temperature, pesticides, insecticides, heavy metals, smoking and alcoholism, etc. 11. Sperm abnormalities: idiopathic oligospermia, weak, deformed sperm, cryptospermia, idiopathic azoospermia.