Various male fertility disorders:

• Azoospermia
• Presence of Antibodies
• Klinefelter's Syndrome
• Hormone Disorders
• Bacterial Infection.
  

Prestesticular causes of infertility

• Hypothalamic disease.
• Isolated FSH deficiency.
• Isolated gonadotropin deficiency (Kallmann's syndrome)
• Hemochromatosis.
• Exogenous hormones (estrogen-androgen excess, glucocorticoid excess, hyper and hypothyroidism).
• Hyperprolactinemia.
• Pituitary disease.
• Pituitary insufficiency (tumors, infilterative processes, operation, radiation).
• Isolated LH deficiency ("Fertile eunuch")
• Congenital hypogonadrotropic syndromes.

Testicular causes of infertility:

• Chromosomal abnormalities (Klinefelter's syndrome, XX disorder (sex reversal syndrome), XYY syndrome).
• Noonan's syndrome (male Turner's syndrome).
• Myotonic dystrophy.
• Bilateral anorchia (vanishing testes syndrome)
• Sertoli-cell-only syndrome (germinal cell aplasia)
• Gonadotoxins (drugs, radiation)
• Orchitis
• Trauma
• Systemic disease (renal failure, hepatic disease, sickle cell disease).
• Defective androgen synthesis or action
• Varicocele
• Cryptorchidism
  

Post testicular causes of male infertility:

• Disorders of sperm transport
• Congenital disorders
• Acquired disorders
• Functional disorders
• Disorders of sperm structure
• Congenital defects of the sperm tail
• Maturation defects.
• Immunological defects.
• Infections.
• Sexual dysfunction.

Investigations:

• Semen analysis.
• Ultrsound scan.
• Chromosomal studies.
• Hormonal studies.
• Immunological studies.
• Sperm Penetration Assays.

Prevention of male infertility:

• Avoiding smoking as it damages sperm DNA
• Avoiding drugs and medications known to cause fertility problems, like steroids and some antifungal medications.
• Avoiding excessive exercise.
• Avoiding exposure to environmental hazards such as pesticides and heavy metals such as lead, mercury and cadmium.
• Avoiding frequent hot baths or use of hot tubs.
• Avoiding tight underwear or pants.
• Eating a diet with adequate folic acid, vitamin C, zinc, calcium, magnesium, selenium, iron loaded food.
• Getting early treatment for sexually transmitted diseases.
• Having regular physical examinations to detect early signs of infections or abnormalities.
• Keeping diseases, such as diabetes and hypothyroidism, under control.
• Practicing safer sex to avoid sexually transmitted diseases.
• Taking a lycopene supplement.
• Wearing protection over the scrotum during athletic activities.