- Undescended Testicle – The primary risk factor for testicular cancer is a problem called undescended testicle(s). Prior to birth, the testicles usually develop in the belly of the fetus and then move down into the scrotum. However in about 3% of males, the testicles do not shift into the scrotum. In some cases, the testicle stays inside the belly. In other cases, the testicle initially moves downward, but gets caught in the groin.Nearly 10% of testicular cancer cases occur in men who have had undescended testicle(s). The risk is greater for men with a testicle in the belly as opposed to one that has moved down at least part way. This factor may not be the direct cause of testicular cancer; other problems may contribute to the cancer risk.
- Family History – A history of testicular cancer adds to the risk. There is an increased risk of developing the cancer if your brother or father has the disease. Though, it is unlikely for a father to pass on the cancer to his son. HIV Infection – There is some proof that men infected with HIV have an elevated risk of testicular cancer. This may be especially the case for men who have AIDS.
- Cancer of the Other Testicle – In cases where a man has been cured of cancer in one testicle, there is an increased risk (3% to 4%) of developing cancer in the other testicle.
- Age – About 90% of testicular cancer cases occur in men between the ages of 20 and 54. Even so, this cancer can affect males of any age, including children and mature men.
- Race and Ethnicity – White American males are about 5 times more probable to develop testicular cancer than are African-American males. Additionally, whites have greater than 3 times the risk of Asian-American and American Indian males. The reason for this distinction is unknown.
Hypogonadism is a condition that is characterized by low (‘hypo’) blood levels of a male hormone called testosterone that is manufactured in the testicles (‘gonads’).
- Normal testosterone production: Special cells in the testicles, called leydig cells, manufacture testosterone from cholesterol. The blood level of testosterone is continually changing according to body’s needs. Special organs in the brain, called the hypothalamus and pituitary, carefully monitor the testosterone level in the blood. When more testosterone is needed, the hypothalamus dispatches a chemical messager in the blood stream that causes the pituitary to release another substance called leutinizing hormone (LH). LH travels in the blood steam to the testicles and stimulates special receptors on the leydig cells to produce more testosterone. The pituitary stops releasing LH when the target testosterone level is met and then LH stimulation resumes again when the testosterone level falls. Testosterone levels are highest in the early morning and lowest later in the day. Most of the male hormone is bound to a protein called sex hormone binding globulin (SHBG). A small percentage of male hormones are ‘free’ or unbound to SHBG. Free testosterone is the active form of male hormone.
- Normal effects of testosterone: Normal reproductive and sexual function depends upon a normal testosterone level. In addition, sufficient testosterone is required for normal bone growth, glucose and lipid regulation, blood cell production, muscle mass, and mental function.
- Abnormal testosterone production: Abnormal testosterone production occurs when there is an abnormality of the hypothalamic-pituitary-testicular function. Blood tests can usually differentiate where the problem lies. Testosterone production gradually decreases with each decade beyond age 40. Approximately 10% of men between the ages of 40-49, 12% between ages 50-59, 15% between ages 60-69, and 25% between ages 70-79 have low total testosterone levels. Free testosterone levels fall more quickly as men age. Approximately 8% of men between the ages of 40-49, 30% between ages 50-59, 45% between ages 60-69, and 70% between ages 70-79 have low free testosterone levels. Although the definition of a low testosterone varies, if a man has a serum testosterone below 300 ng/dl and he has symptoms of hypogonadism, testosterone replacement therapy is warranted.
- Signs of hypogonadism: Signs of hypogonadism include depression, fatigue, decreased sex drive, erectile dysfunction, obesity, enlarged breasts, insulin resistance, anemia, decreased muscle mass, and impaired mental function.
Infertility is often defined as not being able to get pregnant in spite of having frequent, unprotected sex for at least a year. If you and your partner are experiencing difficulty becoming pregnant, you are not on your own. As much as 10-15% of couples in the United States are infertile.
If you’ve been trying to conceive for more than a year, there’s a chance that something may be interfering with your efforts to have a child. Infertility may be attributed to one issue in either you or your partner, or a variety of factors may prevent a pregnancy from occurring or continuing.
A number of factors can weaken sperm count or mobility, or worsen the ability to fertilize the egg. The most common causes of male infertility include irregular sperm production or function, impaired delivery of sperm, general health and lifestyle issues, and excessive exposure to certain environmental elements.
A variety of factors can deteriorate sperm count or mobility, or impair the ability to fertilize the egg. Common causes of male infertility include irregular sperm production or function, diminished delivery of sperm, general health and lifestyle issues, and excessive exposure to certain environmental elements.
Reduced production or function of sperm.
Many cases of male infertility are due to problems with the sperm, such as:
- Irregular shape and movement of sperm. Normal sperm shape and the ability for sperm to move rapidly and accurately toward the egg is crucial for fertilization to occur. If the sperm morphology (shape and structure) are abnormal or the movement is impaired, sperm may not be able to access or penetrate the egg.
- Below normal sperm concentration. Normal sperm concentration is defined as greater than or equal to 20 million sperm per milliliter of semen. Sperm counts of 10 million or fewer per milliliter of semen indicate low sperm concentration. Absolute failure of the testicles to produce sperm is uncommon, affecting very few infertile men.
- Varicocele. This is known as a varicose vein in the scrotum that could prevent normal cooling of the testicle, which may cause reduced sperm count and movement.
- Undescended testicle. This condition occurs when one or both testicles fail to move from the abdomen into the scrotum during fetal development. Due to the fact that the testicles are exposed to the higher internal body temperature, when compared with the temperature in the scrotum, sperm production may be affected.
- Testosterone deficiency. Infertility may result from disorders of the testicles themselves, or an irregularity affecting the hypothalamus or pituitary gland in the brain that produces the hormones that control the testicles.
- Genetic defects. Klinefelter’s syndrome is a genetic defect that occurs when a man has two X chromosomes and one Y chromosome instead of one X and one Y. This causes unusual development of the testicles, resulting in low or absent sperm production and possible low testosterone.
- Infections. Sperm motility can be temporarily affected by certain infections. Repeated attacks of sexually transmitted diseases (STDs), such as chlamydia and gonorrhea, are most often associated with male infertility. These infections can cause scarring and block sperm passage. An occurrence of mumps after puberty may cause inflammation of the testicles and can impair sperm production.
Inflammation of the prostate, urethra or epididymis also may alter sperm motility.
In many cases, no cause for reduced sperm production is found. If sperm concentration is less than 5 million per milliliter of semen, genetic causes may be involved. Slight changes in the Y chromosome can be revealed by a blood test.
Delivery of sperm impaired. Complications with the delivery of sperm from the penis into the vagina can result in infertility. These may include:
- Sexual issues. Often treatable, problems with sexual intercourse or technique may affect fertility. Erectile dysfunction, premature ejaculation, painful intercourse or psychological or relationship problems can contribute to infertility.
- Retrograde ejaculation. Semen enters the bladder during orgasm instead of emerging out through the penis. Diabetes, bladder, prostate or urethral surgery, and the use of certain medications may cause retrograde ejaculation.
- Epididymis or ejaculatory ducts blockage. In some cases, men are born with blockage of the part of the testicle that contains sperm, the epididymis or ejaculatory ducts. Certain men lack the tube that carries sperm (vas deferens) from the testicle out to the opening in the penis.
- No semen (ejaculate). Men with spinal cord injuries or diseases may experience the absence of ejaculate. The sperm is carried from the penis into the vagina by the ejaculate.
- Misplaced urinary opening. A defect at birth may cause the urinary opening to be unusually located on the underside of the penis. The condition may prevent sperm from reaching the woman’s cervix if not surgically corrected.
General health and lifestyle.
Frequent causes of infertility related to health and lifestyle include:
- Emotional stress. Stress may hinder certain hormones needed to produce sperm. Extreme or prolonged emotional stress may affect your sperm. Fertility problems can sometimes become long term and disappointing, producing more stress. Social relationships and sexual performance can affect infertility.
- Malnutrition. Certain vitamin deficiencies such as C, selenium, zinc and folate may contribute to infertility.
Obesity. Unhealthy body weight may contribute to fertility problems in men.
- Alcohol and drugs. Excessive alcohol use or drug dependency may be associated with poor health and lowered fertility.
- Other medical conditions. Male fertility can be affected by severe injury or major surgery. Diabetes, thyroid disease or anemia may be linked to infertility.
- Age. Men older than 35 may experience a gradual decline in fertility.
Excessive exposure to environmental elements such as heat, toxins and chemicals may lead to a reduced sperm count, either direct or indirect. Examples include:
- Pesticides and other chemicals. Studies have shown that herbicides and insecticides can cause female hormone-like effects in the male body and furthermore may be associated with reduced sperm production and testicular cancer. Exposure to lead may also cause infertility.
- Overheating the testicles. Regular use of saunas or hot tubs can increase your core body temperature. This may interfere your sperm production and lower your sperm count. Substance abuse. Use of may temporarily reduce the number and quality of your sperm.
- Tobacco smoking & substance abuse. Smoking may lower your quality and count of sperm.
A varicocele is a dilated spermatic vein. The spermatic vein carries blood from the renal vein to the testicle on the left side and from the vena cava, (the large blood vessel which carries blood from the lower part of the body back to the heart) to the right testicle. Ninety percent of varicoceles involve the left testicle while ten involve only the right side. In a small percentage of cases both spermatic veins are dilated. After varicocele repair, there is an increase in sperm counts in 70-80% of men treated. Sperm counts may rise as soon as three months after surgery but the maximum increase in sperm count may take 6-18 months. Pregnancy can result in up to 50% of cases where the men had a normal sperm count (greater than 60 million per cc) before surgery and in up to 23% of cases of a less than normal sperm count.