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 develop and keep physical male traits. It's also one of the hormones needed for sperm production. Low testosterone is also called testosterone deficiency or hypogonadism.

Low testosterone can lead to problems such as a lower sex drive, weak bones, less muscle mass, less body hair, enlarged breasts, and infertility.

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, other tests may be done.

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:

• Lower sex drive.
• Erection problems.
• Loss of body hair.
• Very small testicles.
• Fertility problems.
• Breast discomfort or enlarged breasts.
• 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'll have a blood test done in the morning. If it shows a low testosterone level, you'll have another blood test to confirm the result. If the second test confirms low testosterone, other tests may be done to look for 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, or in a tablet you place between your cheek and gum.

Another way to raise your testosterone is through pills that you swallow. These pills aren't testosterone. Instead they are other kinds of medicine that work well to raise testosterone levels. They include medicines such as clomiphene.

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 exams 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:

• Your body making too many red blood cells. This may cause blood clots and other problems.
• Headaches.
• Blisters, itching, or redness on the skin under the testosterone patch.
• Soreness in the breasts.
• Symptoms of an enlarged prostate, such as trouble urinating.
• Sudden, dramatic mood swings.
• Hair loss.
• Sleep apnea.
• Acne.