Definition & Overview

Low testosterone, also called testosterone deficiency or hypogonadism, is a condition more commonly experienced by men wherein their bodies produce an inadequate amount of the male hormone. Hypogonadism comes in two types: primary and central. Primary hypogonadism is caused by a problem involving the gonads, or the part of the brain responsible for receiving signals pertaining to hormone production, while central hypogonadism is caused by a brain problem that inhibits the hypothalamus and pituitary gland from producing an adequate amount of testosterone.

The hormone testosterone plays a significant role in the male body since it is responsible for the physical traits of a male individual. It is also responsible for producing sperm. For these reasons, the man’s body normally requires a testosterone range of 300 nanograms per deciliter (ng/dL) with an upper limit of up to 800. If the testosterone levels are lower than the normal range of 300, the patient is considered to have a low testosterone problem, which may bring about some symptoms, especially if the testosterone levels are as low as 200 or 100 ng/dL.

It is possible even for women to experience problems with low testosterone levels. Although testosterone is named as the male hormone, it is produced by both males and females. Women, however, only produce a smaller amount of it compared to men, and this level tends to decline even lower as the woman nears menopause.

Cause of Condition

Low testosterone has been linked to a variety of different factors that may play a role in inhibiting the optimum production of the male hormone. These factors include:

  • Aging
  • Testicular injury
  • Radiation treatment (usually for testicular cancer)
  • Certain medications
  • Obesity
  • Kidney disease
  • Testicular cancer (or the presence of a malignant tumour)
  • Addison’s disease
  • Hypoparathyroidism
  • Turner syndrome
  • Klinefelter syndrome
  • Hormonal disorders affecting all or various types of hormones in the body
  • Infection
  • Type 2 diabetes
  • Liver disease
  • Pituitary gland problems
  • Hypothalamus problems
  • Kallman syndrome
  • Pituitary disorders
  • Tuberculosis
  • Histiocytosis
  • Sarcoidosis
  • Sudden weight loss
  • Nutritional deficiency
  • Bleeding problems
  • Previous brain surgery
  • Haemochromatosis (a condition wherein the body absorbs iron excessively)
  • Genetic factors (in cases where low testosterone production is already detected at birth)

Low testosterone alone is diagnosed through a simple blood test, but a man with testosterone problems may be asked to undergo other tests to determine the cause of the condition and rule out the possibility of other medical problems as the cause. The blood test is preferably conducted early in the morning when testosterone levels tend to be at their highest, especially when the patient is still young. He may also be asked to take several tests owing to the fact that a man’s testosterone levels may fluctuate significantly during a 24-hour period. If the results show a low testosterone level, many endocrinologists perform the test again to confirm the diagnosis.

To confirm the blood test results, the doctor may also request for an examination of the patient’s muscle mass and testing for other sex hormones such as the FSH (follicle stimulating hormone) and the LH (luteinizing hormone), both of which are produced by the pituitary gland. Female patients also need to undergo an estrogen level test.

If the hormone problem is found to be caused by an underlying disease or health condition, it is important to treat the disease first. Although the testosterone problem may be separately addressed, there is no guarantee that the problem will not recur.

Key Symptoms

Men who have compromised testosterone production and, therefore, do not receive enough of the all-important male hormone may experience the following symptoms:

  • Concentration problems
  • Decreased sex drive
  • Low semen volume
  • Depression
  • Fatigue
  • Breast growth
  • Compromised penile and testicular growth
  • Osteoporosis
  • Infertility
  • Weakness
  • Disturbed sleep
  • Feelings of worthlessness
  • Erectile dysfunction
  • Bone density problems
  • Increase in body fat
  • Decrease in muscle mass
  • Low mood

Women also experience unique symptoms, such as:

  • No menstruation period
  • Hot flashes
  • Slow breast growth
  • Milky discharge coming from the breasts
  • Body hair loss

Since these symptoms can also be caused by myriads of other possible health problems, it is sometimes hard to detect a low testosterone problem by its symptoms alone. Also, not all men with low testosterone levels experience symptoms; sometimes, the problem does not cause any noticeable change in the body. These are the reasons why men are instead advised to undergo regular checkups, whether or not they feel symptoms.

Who to See & Types of Treatments Available

Decreased testosterone production and inadequate testosterone levels are countered through the supplementation of the said hormone. This treatment procedure is called testosterone replacement wherein the patient is given an additional supply of testosterone to compensate for the amount the body cannot produce. The hormone is usually delivered through an injection, a tablet that is placed between the cheek and gum, a patch, implantable pellets, or a gel. Testosterone injections are said to be the most effective treatment type for men who are trying for a baby since they can also stimulate sperm count and motility. Thus, hormone replacement therapy is the most common type of treatment used for men suffering from decreased testosterone levels, and is also used to help men who are having erection issues.

The least preferred treatment option is the gel type testosterone supplement, which can be very inconvenient since the patient has to be extra careful not to let the gel touch another person’s skin.

The most recent development is delivering additional testosterone by implanting hormone pellets just under the skin, usually in the buttocks region. This form of treatment can continually release the right amount of testosterone for three to four months, making it also a highly convenient option.

Men receiving extra testosterone may notice some noticeable effects, such as an improvement in sexual desire, increased muscle mass, and lower levels of bone loss. Most patients undergoing hormone replacement therapy for low testosterone also report a general improvement in their energy level and overall health.

Hormone replacement therapies, however, are associated with several side effects, such as:

  • Sleep apnoea
  • Acne
  • Trouble urinating
  • Blisters
  • Skin redness (only when a testosterone patch is used)
  • Itching
  • Enlargement of the prostate
  • Infertility

Another treatment option available for men with low testosterone levels is taking medication; the drugs given are not the hormone itself but are effective in stimulating normal testosterone production to raise the body’s testosterone levels. Examples of these medications are letrozole and clomiphene, among many others.

These treatments are carried out by an endocrinologist, a medical specialist focused on diagnosing and treating diseases related to the body’s hormone production. If you go to your general physician or family doctor to report your symptoms, you will be referred to an endocrinologist who will prescribe the best course of treatment for your condition.


  • Spyros Mezitis, MD, PhD, endocrinologist, Lenox Hill Hospital, New York.
  • Jason Hedges, MD, PhD, urologist, Oregon Health and Science University, Portland, Ore.
  • The Hormone Foundation: "Low Testosterone and Men's Health."
  • The Hormone Foundation: "Patient Guide to Androgen Deficiency Syndromes in Adult Men."
  • Patient Education Institute: "Low Testosterone Reference Summary."
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