Condition Basics

What is low testosterone?

Men who have low testosterone do not make enough of the male hormone called testosterone. This hormone allows men to produce sperm and to develop and keep normal physical male traits. Low testosterone is also called testosterone deficiency or hypogonadism.

Low testosterone can lead to problems such as loss of sex drive, erection problems, infertility, and weakened bones.

What causes it?

Many things can cause this problem, such as:

• Aging. It's normal for testosterone to decrease as you age.
• Injury to the testicles, or surgery or radiation treatment in the groin area.
• Certain medicines.
• Having a long-term medical condition, such as kidney or liver disease or obesity.
• Problems related to the pituitary gland or hypothalamus.

Low testosterone also can be present at birth.

A blood test is usually done to find out if you have low testosterone. If your doctor thinks low testosterone could be related to another medical problem, he or she may do other tests.

Since testosterone normally decreases with age, your doctor can help determine whether your symptoms are from low testosterone and whether you could benefit from treatment.

What are the symptoms?

Symptoms of low testosterone in men may include:

• Loss of sex drive.
• Erection problems.
• Loss of body hair.
• Very small testicles.
• Fertility problems.
• Breast discomfort.
• Hot flashes.
• Loss of height.
• Weakened bones.

How is it diagnosed?

Your doctor will examine you and ask about your symptoms and past health. You will have a blood test. If it shows a low testosterone level, you will have another blood test to confirm the result. If the second test confirms low testosterone, other tests may be done to find the cause.

How is low testosterone treated?

Treatment may depend on the cause. Low testosterone that causes symptoms usually is treated with testosterone hormone. This is called testosterone replacement. You can get it in different ways, such as in a shot, through a patch or gel on the skin, a pill you swallow or in a tablet you place between your cheek and gum.

Testosterone replacement may improve your sexual desire, increase your muscle mass, and help prevent bone loss. Many men with low testosterone levels report that they feel better and have more energy while taking testosterone.

Testosterone may be used to treat some men who have erection problems.

What are some cautions?

The evidence from studies isn't clear about whether taking testosterone lowers or increases the risk of heart attack, stroke, or blood clots in the veins.

Experts don't know for sure if taking testosterone affects the risk of prostate cancer. Your doctor may recommend regular examinations and blood tests to check for problems.

Testosterone can affect your fertility. If you are trying to have a child, you may want to ask your doctor if you can take a medicine that doesn't affect fertility.

Side effects

Side effects of testosterone replacement may include:

• Blisters, itching, or redness on the skin under the testosterone patch.
• Soreness or increase in the size of the breasts.
• Symptoms of an enlarged prostate, such as trouble urinating.
• Sleep apnea.
• Acne.