Male infertility can arise from a variety of medical, environmental, and lifestyle 男性不妊 that affect sperm production, quality, or delivery. The most common causes include:
Medical Causes:
- Sperm Production Disorders:
- Low sperm count (oligospermia) or no sperm production (azoospermia).
- Abnormal sperm morphology or reduced motility.
- Conditions like varicocele (enlarged veins in the scrotum) disrupt sperm development.
- Hormonal Imbalances:
- Issues with the hypothalamus or pituitary gland can lead to insufficient levels of testosterone, which is crucial for sperm production.
- Genetic Disorders:
- Chromosomal abnormalities like Klinefelter syndrome.
- Y-chromosome microdeletions, which directly affect sperm production genes.
- Infections and Inflammation:
- Sexually transmitted infections (STIs) or epididymitis (inflammation of the epididymis).
- Mumps orchitis (testicular inflammation caused by mumps) can permanently damage the testes.
- Obstruction of Reproductive Tract:
- Blockages in the vas deferens or epididymis can prevent sperm delivery.
- Often caused by infections, surgery, or congenital issues (e.g., absence of the vas deferens in cystic fibrosis).
Environmental and Lifestyle Factors:
- Exposure to Toxins:
- Pesticides, heavy metals, and industrial chemicals can impair sperm production.
- Heat Exposure:
- Prolonged exposure to high temperatures (e.g., saunas, tight clothing) affects sperm quality.
- Lifestyle Choices:
- Smoking, excessive alcohol, and recreational drug use harm sperm health.
- Obesity and Poor Nutrition:
- Excess body fat disrupts hormonal balance, reducing sperm production.