Signs and Symptoms of Low Testosterone Levels In Teenager

If you have a boy going through puberty, you may need to know the signs of low testosterone. Puberty usually starts around the age of 13 to 14, and you will notice changes in your son. At first you may notice voice cracking, hair growth on the face and arms, along with increasing muscle tone. If your son goes through delayed puberty, he may have a low testosterone condition known as, hypogonadism. It is good to watch for the signs of this condition, as there are treatments available.

 What Are The Signs of Low Testosterone in Teenager?

If your son seems to be developing slowly, there may be an issue with low testosterone. The signs may be subtle and hard to notice. Your teenager may also be noticing that he is “different” from other boys, but have a hard time telling you about it.

First, a little bit about male sexual development. As the reproductive system in boys matures, they begin to produce the sex hormones that make semen. Males are born with all of the reproductive system intact, but they cannot reproduce children until they have mature semen. This usually occurs between 9 and 15 years of age.

The pituitary gland in the brain begins to secrete stimulating hormones that tell the reproductive organs to begin maturing. The testicles will start by making the hormone, testosterone. After the age of 15, the signs include

  • Voice Tone Higher/Softer
  • Lack of Body Hair Growth
  • Shorter Stature
  • Lack of Muscle Tone or Muscle Growth
  • No Pubic Hair or Underarm Hair
  • Smaller Penis and Testicles (They may not tell you about this)
  • Arm and Leg Length Out of Proportion (Longer)
  • Breast Development (Rare)
  • Extreme Fatigue
  • Trouble Focusing
  • Headaches
  • Hot Flashes

Your son may notice in the gym showers that his body is developing slower than his peers. He may or may not tell you that he is noticing these signs. Your child’s pediatrician may discuss these things during a yearly physical, and may notice slow development.

Parents may notice the above signs when they see their child next to friends. The most obvious are; short stature, lack of facial or body hair growth, and vocal tones. Most young boys that are going through puberty tend to have “cracking voices,” a phenomenon that occurs with vocal cord maturation.

What Causes Low Testosterone in Teenagers?

Low testosterone is related to a condition known as, hypogonadism. This is caused by a few different things like:

Genetic Disorder or Birth Defect

A birth defect may cause the testicles to remain high in the abdomen and not descend. Undescended testicles are unable to produce testosterone. Also, a genetic disorder Klinefelter syndrome may cause testosterone production to remain low. This may cause slower development of sexual characteristics and possible male infertility. 

Another birth defect is, Kallmann syndrome. This affects the hypothalamus and pituitary gland in the brain. They fail to develop properly and may not produce enough testosterone stimulating hormones.

Mumps Infection

Mumps, one of the communicable childhood infections can cause problems with puberty and fertility in males. The infection can go into the testicles and cause damage to the testosterone producing cells. If your son had mumps as a small child, you will need to watch for signs of low testosterone in teenager or even young adult years.

Radiation/Cancer Treatment

If your son was treated for cancer with radiation anywhere near the lower abdomen or genital region, it may have lowered the production of testosterone. The good news is it is most often just temporary, but large amounts of radiation may cause permanent damage. Newer technology is now better at focusing radiation beams only on the parts needing treatment, but if treatment is for testicular cancer then infertility may result.


Injury to the scrotum can damage the testicles and reduce testosterone production. This is common in full contact sports, and bicycle riding. Injury can also occur from a blow due to a punch or kick to the area during a physical altercation. While these usually heal fine, very traumatic injuries to the area may cause permanent damage.

 High Iron Levels

If iron levels in the blood are too high, it may affect pituitary function. This can lead to failure of the testicles to produce testosterone.

How To Deal With It

There are some ways to help you deal with signs of low testosterone in teenager. You will need to approach conversations about the issue with them gently. As a parent, you will want to help and these tips will make it easier:

  1. Find someone they trust to open up conversations. They may have an easier time talking to dad, an uncle, or a good friend. They may even feel comfortable opening up to their pediatrician about what is going on with their body. The important thing is to try to get them to talk about it, comfortably.
  2. Stress the importance of sports safety. If your son plays sports, talk to them about being safe “down there.” Let them know why, and provide protection devices like a “cup” also known as a “jock-strap.” Good support will help prevent injuries in full-contact sports.
  3. Immunize against mumps. If you so choose, there is an immunization to protect against mumps. This is on the regular immunization schedule for children and part of the measles/rubella series or MMR vaccine. This is especially important in boys to prevent mumps related testicular damage.
  4. Ask your pediatrician for printed information for your teen. Many pediatricians have printed information about puberty that is written in easy to understand language for teens. They can read about the signs they can expect to show up and about what age. This may lead them to ask you questions if something doesn’t feel or seem right.
  5. Look into other causes. If your pediatrician has ruled out mumps infection, or injury, they may need to look into other causes. If you have a family history of low testosterone or infertility in males, let your doctor know. They may need to look for a genetic cause.