Andrology: Definition and Areas That This Branch of Medicine Studies

It is the branch of medicine related to men’s health, mainly male infertility and sexual dysfunction.

Andrology is the study of man (Greek Andros, man). It is the male counterpart of gynecology.

Andrology deals with the treatment of many problems regarding male sexual health. These are some of the most common problems that andrology deals with:

Male fertility problems

Reproduction (or making a baby) is a simple and natural experience for most couples. However, for some couples, it is tough to conceive.

Male infertility is diagnosed when reproductive problems have been found in the male partner after testing of both partners.

Male infertility can be caused by problems that affect sperm production or the sperm transport process. With the results of medical tests, the doctor can find the cause of the problem. There may be genetic causes of male infertility.

When a couple is having medical investigations for infertility, testing the male partner usually includes semen analysis. (This test is also used to confirm a successful vasectomy.)


A male diagnosed with cancer as an adolescent or young adult should consider his fertility preservation options, as he may wish to have children in the future.

What is male infertility?

A man’s fertility generally depends on the quantity and quality of his sperm. If the number of sperm a man ejaculates is low or if the sperm is of poor quality, it will be difficult, and sometimes impossible, for him to cause a pregnancy.

Male infertility is diagnosed when, after evaluating both partners, reproductive problems have been found in the male.

How common is male infertility?

Infertility is a widespread problem. The problem lies solely with the male partner for about one in five infertile couples.

One in 20 men has some fertility problem with a low number of sperm in their ejaculate. However, only one in 100 men does not have sperm in their ejaculation.

What are the symptoms of male infertility?

In most cases, there are no apparent signs of infertility. Sex, erections, and ejaculation generally happen without difficulty. The amount and appearance of the ejaculated semen generally appear normal to the naked eye. Medical tests are needed to find out if a man is infertile.

What Causes Male Infertility?

Male infertility is generally caused by sperm production or sperm transport problems. Through medical tests, the doctor can find the cause of the problem.

About two-thirds of infertile men have a problem producing sperm in the testicles. Either few sperm are made, and the sperm that are produced do not work correctly.

Sperm transport problems are found in about one in five infertile men, including men who have had a vasectomy but now want more children.

Blockages (often called blockages) in the tubes that carry sperm away from the testicles into the penis can cause a complete lack of sperm in the ejaculated semen.

Other less common causes of infertility include:

  • Sexual problems affect whether semen can enter a woman’s vagina for fertilization (one in 100 infertile couples).
  • Low hormones are produced in the pituitary gland: which acts on the testicles (one in 100 infertile men).
  • Sperm antibodies:  found in one in 16 infertile men. In most men, sperm antibodies will not affect the chance of pregnancy, but in some men, sperm antibodies reduce fertility.

Known causes of male infertility

Problems related to sperm production:

  • Chromosomal or genetic causes.
  • Undescended testicles (failure of the testicles to descend at birth).
  • Infections
  • Torsion (twisting the testicle into the scrotum).
  • Varicocele (varicose veins of the testicles).
  • Medicines and chemicals.
  • Radiation damage
  • Unknown cause.

Problems related to sperm blockage:

  • Infections
  • Prostate-related problems.
  • Absence of vas deferens.
  • Vasectomy

Sexual problems related to erection and ejaculation:

  • Retrograde and premature ejaculation.
  • Failure of ejaculation.
  • Erectile dysfunction.
  • Infrequent sexual intercourse.
  • Spinal cord injury.
  • Prostate surgery
  • Nerve damage
  • Some medications

Hormone-related problems:

  • Pituitary tumors.
  • Congenital lack of LH / FSH (pituitary problem from birth).
  • Use of anabolic (androgenic) steroids.

Sperm antibodies:

  • Vasectomy
  • Injury or infection in the epididymis.
  • Unknown cause.

How is male infertility diagnosed?

If a couple has been trying a pregnancy without success, they should go to their local doctor or family planning clinic and have some initial tests. Infertility should be considered a couple of problems that require review by both the male and female partners, even if a couple has a child from another relationship.

Male infertility can be a sign of other (possibly undiagnosed) health problems such as testosterone deficiency or coexisting testicular cancer, so it must be investigated.

Diagnosis may include a man’s medical history and a physical exam along with a semen analysis to check the number, shape, and movement of sperm in ejaculation.

Blood tests may also be done to check the levels of hormones that control sperm production or for genetic testing. Sometimes testicular biopsies or testicular ultrasounds are done.

How is male infertility treated?

One in eight infertile men has a treatable condition, and after treatment, couples can become pregnant naturally.

In some cases, the doctor will recommend that the couple seek assisted reproductive technologies (ART), such as IVF (in vitro fertilization). ART does not cure or treat the cause of infertility, but it can help couples achieve pregnancy, even if the man’s sperm count is meager.

What is ICSI?

Intracytoplasmic sperm injection (ICSI) is a form of IVF in which a single sperm is placed directly into each egg by piercing the egg’s outer covering.

ICSI is particularly helpful for men with poor sperm production. Sperm is obtained from semen or is carefully extracted from the testicle or epididymis.

ICSI can achieve pregnancies even when only a few sperm are produced.

As for IVF, after fertilization, the resulting embryos are placed in the woman’s uterus.

Can anything be done to prevent male infertility?

It is best to avoid smoking, excessive alcohol, sexually transmitted infections, heat stress from tight underwear, and anabolic steroids (used for bodybuilding or sports purposes) as these factors can harm sperm production.

If you work in an occupation that can affect your fertility, it is essential to wear protective clothing and follow all occupational health and safety guidelines. Couples trying to conceive are encouraged to avoid exposure to possibly harmful chemicals.

Due to the possible effects on fertility, it is essential to tell your doctor if you received hormone treatment or had surgery as a child to move your testicles into the scrotum.

Can Old Age Cause Male Fertility Problems?

Healthy menage 70 and over can still have children. However, the time it takes for a couple to get pregnant is longer when a man is middle-aged or older.

This may include decreased sexual activity, decreased semen volume, changes in sperm motility (movement), fewer motile sperm, and possibly lower sperm function and quality of DNA.

The possibility that the boy has some genetic or chromosomal problem also increases for older men.

What emotions can a man experience when he is diagnosed with infertility?

Men may be surprised when they find out that they are infertile. There is still a common but incorrect belief that infertility is a woman’s problem. Therefore, when men are told that there is a sperm problem, they are often unprepared.

Being told there is a sperm problem can affect a man’s sense of masculinity, sexuality, and potency. Most infertile men, at some point, struggle with the idea that they are not capable of doing what other men can do.

An emotional response to infertility is normal. Talking to a doctor, sex therapist, or counselor can help some men with their feelings about infertility.

Genetic causes of infertility

What genetic problems affect sperm production (or sperm transport)?

Some chromosome changes or genetic mutations cause abnormal sperm production or blockages in sperm flow, leading to male infertility.

The most common genetic causes of infertility are chromosomal conditions that affect sperm production. These include:

  • Síndrome de Klinefelter.
  • Y chromosome deletions.
  • Other genetic problems, such as Down syndrome.

Infertility due to mutations in individual genes is less common. The congenital absence of the vas deferens, where there is a blockage of sperm flow, is caused by mutations in the gene for cystic fibrosis.

Other genetic disorders are likely to be found in the future that help explains other sperm production problems that currently have no known cause.

What are Y chromosome deletions, and how are they treated?

Some men lack genetic material on their Y chromosome that is important for sperm production.

Deletions on the Y chromosome cause poor sperm production in about one in 20 men with a low sperm count (less than 5 million sperm per ml).

Y chromosome deletions occur spontaneously during embryo development, so parents and siblings are generally unaffected.

Several Y chromosome deletions can be found with a blood test.

About half of men with Y chromosome deletions have enough sperm to use in ICSI; however, their male offspring will also have Y chromosome deletion and fertility problems.

Congenital absence of the vas deferens

Congenital absence of the vas deferens (CAVD) is a rare genetic problem that causes infertility.

Various parts of the reproductive tract (including the vas deferens, most of the epididymis, and seminal vesicles) are missing from birth (congenital). Sperm production usually occurs, but sperm cannot pass from the testicles to ejaculation.

Most men with CAVD have a mutation in the cystic fibrosis gene (CFTR). However, in most men with CAVD, the type of mutation means that they do not have the severe lung and bowel problems that are a hallmark of cystic fibrosis.

Cystic fibrosis is a severe disease caused by specific mutations in the CFTR gene, with early-life symptoms. Most men with cystic fibrosis also have an absence of vas deferens.

How is the congenital absence of the vas deferens (CAVD) treated?

There are no surgical treatments for CAVD, but it is generally possible to collect sperm directly from the testicle or the epididymis that can be used in assisted reproductive treatments, such as ICSI, when a man wishes to have a child.

What should men with CAVD think?

The man and his partner should undergo a blood test for mutations in the cystic fibrosis gene (CFTR) before starting assisted reproduction treatments.

About one in 25 of the general population (including women) has a CFTR mutation. Therefore, both must be tested before starting IVF treatment.

Couples where the man has CAVD, should have genetic counseling. If both partners have CFTR mutations, there is a one in four chance that your child will have cystic fibrosis.

If such a couple uses IVF to achieve pregnancy, the fertilized eggs can be tested to see if the embryo has cystic fibrosis. This is called a pre-implantation genetic diagnosis. Only embryos not affected by cystic fibrosis will be transferred to the woman’s uterus.

Down syndrome

Down syndrome can affect both men and women. People with this condition have an extra copy of chromosome 21 and have a variety of disabilities.

They have distinctive physical characteristics and varying degrees of intellectual disability. Men with Down syndrome also have abnormal sperm production and are generally infertile.

How are genetic problems treated?

At this stage, there are no treatments that can fix the genetic problems that cause poor sperm production or transport.

While some men with genetic problems can father children naturally, IVF, ICSI, or other forms of assisted reproduction offer the best opportunity for these men to have biological children.

What should men with genetic problems think?

Some genetic problems, such as Y chromosome deletions, will be passed on to any male child born through sperm in IVF or ICSI procedures. However, for most men with suspected genetic causes of infertility, we still do not know if their children will be affected.

Investigation of men with unexplained low sperm counts (less than 10 million sperm/ml) should include a karyotype and, when there are less than 5 million sperm/ml, also a Y chromosome deletion test.

Couples where the man has CAVD should have genetic counseling to discuss the risk of cystic fibrosis in their children and the possibility of genetic diagnosis prior to implantation and selection of embryos in IVF.

Penis problems


What are penile cysts?

Sometimes the sebaceous glands (oil-producing glands) in the penis and scrotum can become enlarged and blocked, turning into cysts. Cysts usually do not need treatment, but they can sometimes become painful and infected if they continue to grow.

What are penis ulcers?

Ulcers appear as craters on the skin and often have clear fluid or pus in the crater. A single ulcer on the penis can be severe and should be checked by a doctor right away. The causes of a single ulcer include syphilis, tropical diseases, and penile cancer.

Multiple ulcers are more common and less severe but still need to be managed by a doctor. The herpes virus is the most common cause of multiple ulcers on the penis.

What are penile papules?

Papules are small raised bumps on the skin, and most do not have a severe cause. “Pearly penile papules,” a common type, appear as one or more rows of small smooth bumps around the back of the glans penis (head of the penis).

These are often mistaken for genital warts; however, pearly penile papules are not infectious and do not need treatment.

Causes of other papules on the penis include psoriasis (a skin condition) and sexually transmitted infections such as genital warts.

What are genital warts?

Genital warts are caused by the human papillomavirus (HPV). Warts often occur in groups and can be very small. Genital warts are spread through skin-to-skin contact, so it is essential to use condoms if you or your partner are infected.

Genital warts are treated with topical antiviral ointment or, if that does not work, frozen with topical liquid nitrogen.

Although these treatments remove warts, they do not remove the HPV virus, and warts can reappear on the skin or in the eye of the penis. An inspection of the inside of the penis may be necessary to treat warts fully.

There is a National HPV Vaccination Program in Australia, where the HPV vaccine is provided free of charge to all men and women aged 12 or 13.

What is Peyronie’s disease?

Peyronie’s disease (named after François de la Peyronie, surgeon to King Louis XV of France) is the hardening of the tissues (fibrosis) in the penis.

A lump or plaque (scar tissue) forms on the lining of the erectile tissue that contains much of the blood in the penis during erection. In most cases, a hard lump can be felt at the point where the penis curves.

The hardened area or plaque prevents regular stretching and can affect the size and shape of the erect penis. In severe cases, the plaque can include the muscle and arteries of the penis leading to erection problems.

What is penile cancer?

Cancer develops in the penis when cells on the surface divide uncontrollably to form a tumor.

Most penile cancers develop from skin cells on the penis; Most (95%) of the penis come from a particular type of skin cell and are called “squamous cell cancers.”

These cancers generally occur on the foreskin of uncircumcised men, but they can occur anywhere on the penis. Most of these cancers grow very slowly and can be cured if caught early.

Cancer of the penis is rare. In 2012, 108 new cases were diagnosed in Australia; up to 1 in 1000 men develop penile cancer in their lifetime.

It is often not known why penile cancer develops, but some factors are known to make cancer more likely to develop.

These risk factors include chronic (long-term) infection with HPV; not being circumcised; phimosis (where the foreskin is too tight and cannot be pulled back); balanitis (inflammation of the glans penis); smoking; and being of legal age.

There are several treatments for penile cancer. The treatment chosen depends on the type and stage of cancer, the man’s general health, and personal preferences for the type of treatment and associated side effects.

The primary treatment is surgery. Other treatments include laser treatments, chemotherapy, and radiation therapy; These treatments can be given after surgery or instead of surgery.


Priapism is an erection that lasts more than three hours and is usually very painful. Blood is trapped in the penis and does not return to circulation. It is not always related to sexual stimulation.

If priapism is not treated, it can damage the erectile tissue in the penis and make a man unable to get an erection. Priapism can happen to men at any age.

What Causes Priapism?

The most common cause of priapism is a side effect of erectile dysfunction treatment, particularly penile injections. About a quarter of all other priapism cases are related to medical conditions such as advanced cancer, leukemia, and sickle cell anemia.

Other causes include damage to the nervous system, injury to the penis, some medications, and illegal drugs. Sometimes the cause of priapism is unknown.

How is priapism treated?

It is essential to see a doctor immediately, as the sooner it is treated, the minor damage to the erectile tissue. If you seek treatment within four to six hours, your doctor may give you a decongestant medicine to help your erection decrease.

Another option is for the doctor to use a needle and syringe to release the extra blood trapped in the penis. If this does not work, surgery may be needed to stop permanent damage to the penis.

Penis injuries

What is a fractured penis?

A penile fracture can occur when too much force on an erect penis and the fibrous tissue within the penis breaks. When the penis fractures, a clicking or popping sound is heard, the erection goes down, and bruising and pain occur.

What Causes a Fractured Penis?

Penile fractures are rare. The leading cause of a penis fracture is vigorous intercourse or vigorous masturbation.

How is a fractured penis treated?

A fractured penis needs urgent surgery. It is best for the best result from surgery if it occurs within six hours of the fracture, if possible.

In rare cases, if the surgery is not done quickly enough, there can be long-term problems with erectile dysfunction, scarring of the penis, or deformed or bent erections.

Low testosterone levels

What are androgens?

Hormones are chemical messengers produced by the body’s glands that are transported in the blood to act on other organs of the body. Hormones are necessary for growth, reproduction, and well-being.

Androgens are male sex hormones that increase at puberty and are needed for a boy to develop into a sexually mature adult who can reproduce. The most important androgen is testosterone.

What is testosterone?

Testosterone is the most important androgen (the male sex hormone) in men and is necessary for normal sexual and reproductive function.

Testosterone is essential for the physical changes during male puberty, such as the development of the penis and testicles, and the characteristics typical of adult men, such as facial and body hair and the male physique.

Testosterone also acts on the cells of the testes to produce sperm.

Testosterone is also essential for general good health. It helps the growth of bones and muscles and affects mood and libido (sexual desire). Some testosterone is converted to estrogen, the female sex hormone essential for men’s bone health.

Testosterone is produced mainly in the testes. The adrenal glands, which are walnut-sized glands that sit on top of the kidneys, also produce a small amount of testosterone.

How do the testicles control hormones?

The pituitary gland and hypothalamus, located at the base of the brain, control the production of male hormones and sperm. Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) are the two essential messenger hormones produced by the pituitary gland and act on the testes.

LH is needed for the Leydig cells in the testes to produce testosterone, the male sex hormone. Testosterone and FSH from the pituitary gland work together on the testes’ seminiferous tubules (sperm-producing tubes) to produce sperm.

Early childhood:

  • The penis and testicles do not grow to the expected size.

Early teenage years (puberty):

  • Lack of penetration in normal puberty.
  • Poor development of facial, body, or pubic hair.
  • Poor muscle development
  • The voice does not intensify.
  • Height increase.
  • Development of the breast (gynecomastia).


  • Mood swings (low mood and irritability).
  • Poor concentration
  • Low energy
  • Reduction of muscle strength.
  • Increase in body fat.
  • Longer time to recover from exercise.
  • Low libido (low interest in sex).
  • Difficulty obtaining and maintaining erections.
  • Low semen volume.
  • Reduced growth of beard or body hair.
  • Breast development (gynecomastia).
  • Hot flashes, sweats.
  • Osteoporosis (thinning of the bones).

Later life (after age 60):

  • Mood swings (low mood and irritability).
  • Poor concentration
  • Easy fatigue
  • Poor muscle strength.
  • Increase in body fat.
  • Low libido (low interest in sex).
  • Difficulty getting and maintaining erections.
  • Breast development (gynecomastia).
  • Osteoporosis (thinning of the bones).

What Causes Androgen Deficiency?

Androgen deficiency can be caused by genetic disorders, medical problems, or damage to the testicles or pituitary gland.

Androgen deficiency occurs when there are problems within the testicles or with the production of hormones in the brain. A common chromosomal disorder that causes androgen deficiency is Klinefelter syndrome.

How is androgen deficiency diagnosed?

An androgen deficiency diagnosis involves having a thorough medical evaluation and at least two blood samples (taken in the morning on different days) to measure hormone levels.

The diagnosis should not be based simply on the symptoms as they could be caused by other health problems that require different treatment. The diagnosis of androgen deficiency is only confirmed when blood tests show a lower than average testosterone level.

What is the range of “normal” testosterone?

A reference range is used as a guide when analyzing labs and doctors to decide whether a person’s hormone levels are normal or low and whether treatment may be needed.

Testosterone is measured in units called nanomolar. The ‘normal’ testosterone reference range for healthy young adult men is approximately 8-27 nanomolar, but these figures vary according to measurement systems.

How is androgen deficiency treated?

Androgen deficiency is treated with testosterone therapy, Which means administering testosterone in doses that return testosterone levels in the blood to normal.

Testosterone is prescribed for men with androgen deficiency confirmed by blood tests. Once started, testosterone therapy is usually continued for life, and the man should be seen regularly by a doctor.

What are the primary forms of testosterone therapy?

In Australia, testosterone therapy is available in injections, gels, creams, patches, and tablets, and it works very well for men with a confirmed androgen (testosterone) deficiency.

The type of treatment prescribed may depend on the patient’s convenience, familiarity, and cost. Commercial testosterone products contain only the natural testosterone molecule chemically produced from plant materials.

What are the side effects of testosterone therapy?

Side effects are not expected because testosterone therapy aims to bring a man’s testosterone levels back to normal.

However, testosterone therapy can increase the growth of the prostate gland, which can worsen the symptoms of benign prostate enlargement (such as the need to urinate more frequently).

In the case of prostate cancer, testosterone therapy is not used because of concerns that it may cause the tumor to grow.

Too high a dose of testosterone can lead to acne, weight gain, gynecomastia (breast development), male pattern hair loss, and mood swings. A doctor and the low testosterone dose should manage any side effects.

Can Herbal Products Help Androgen Deficiency?

Many herbal products are marketed, especially on the Internet, as treatments that can act like testosterone and improve muscle strength and libido (sex drive).

However, there are no known herbal products that can replace testosterone in the body and are used to treat androgen deficiency.

Can you do anything to prevent androgen deficiency?

There are no known ways to prevent androgen deficiency caused by damage to the testicles or the pituitary gland. However, if you live a healthier lifestyle and manage other health problems, your testosterone levels may improve if your low testosterone levels are caused by another disease.

Not all men have a drop in testosterone levels with age. A healthy lifestyle can help you maintain normal testosterone levels.