Male infertility has many potential causes. Problems with sperm production can result from genetic conditions, undescended testicles, infections, or varicocele, which is swelling of veins in the scrotum. Hormone imbalances involving testosterone, thyroid, or pituitary glands can reduce sperm production. Blockages in tubes that carry sperm may occur due to injury, infection, or prior surgery. Environmental factors like exposure to heavy metals, radiation, or certain chemicals can harm sperm health.
Lifestyle factors significantly impact male fertility. Smoking, heavy alcohol use, and drug use can reduce sperm quality. Being overweight or obese affects hormone levels and sperm production. Nutrient deficiencies, including low selenium levels, may impair sperm development and motility. Chronic stress, poor sleep, and lack of exercise also contribute to fertility problems. Age plays a role, as sperm quality declines gradually after age 40.