Testicles might not be anyone’s favorite topic at the lunch table, but understanding them is an important part of knowing your body. This guide explains what testicles do, how they change during puberty, what’s normal, and when to ask for help — in clear, honest language.
What Testicles Actually Are
Testicles are two small, oval organs that usually sit in a skin pouch called the scrotum, just below the penis. They are part of the male reproductive system and are sometimes called “testes” or “balls.” Their job is to make sperm (for reproduction) and testosterone (a major male sex hormone).
Each testicle is surrounded by layers of protective tissue and is connected to the body by a cord-like structure called the spermatic cord, which carries blood vessels, nerves, and a tube that eventually joins the rest of the reproductive system.
Why the Scrotum Hangs Outside the Body
Unlike organs such as the heart or liver, testicles sit outside the main body cavity. This is not a design mistake — it is about temperature control. Sperm are made best at a slightly cooler temperature than the rest of the body.
The scrotum works like a built-in “climate control” system. When it is cold, the muscles in the scrotum tighten and pull the testicles closer to the body. When it is warm, the scrotum relaxes and lets the testicles hang lower, helping to keep them cool enough to make healthy sperm.
Inside the Testicles: The Basic Parts
Even though testicles look simple from the outside, they are packed with important structures on the inside. Understanding the basics can make medical terms less scary if a doctor ever needs to examine you or explain something.
- Seminiferous tubules: Long, coiled tubes where sperm are actually made.
- Sertoli cells: Support cells inside the tubules that help developing sperm grow and stay nourished.
- Leydig cells: Cells between the tubules that produce testosterone.
- Rete testis and ducts: Small channels that collect sperm and start them on the path out of the testicle.
- Epididymis: A long, folded tube on the back of each testicle where sperm mature and are stored.
Testicles and Puberty: What Changes
Puberty in people with testicles usually starts somewhere between ages 9 and 14, but “normal” covers a wide range. One of the earliest signs is that the testicles start to grow and the scrotum changes in color and texture.
As puberty continues, testosterone levels rise, sperm production begins, and other changes follow — like penis growth, pubic hair, muscle development, and a deeper voice. These changes rarely happen all at once and can feel uneven or awkward for a while.
Typical Puberty Milestones Involving Testicles
- Testicles increase in size gradually.
- The scrotum becomes looser and may look darker or more wrinkled.
- Pubic hair starts to appear around the base of the penis and scrotum.
- Occasional mild aching or a “heavy” feeling may happen during growth.
Normal Differences: Shape, Size, and Position
No two people’s testicles look exactly the same, and that is normal. In most people, one testicle hangs a little lower than the other, and one may be slightly bigger. This natural unevenness helps prevent them from pressing directly into each other.
What matters more than perfect symmetry is whether anything changes suddenly. Gradual growth over years is expected. A sudden lump, rapid increase in size, or new pain is something to pay attention to.
Common Normal Variations
- One testicle slightly larger than the other.
- One testicle hanging lower or more forward.
- Scrotal skin that looks darker or more wrinkled after puberty starts.
- Testicles that seem to move up when cold or during exercise.
When Testicles Move Around
Testicles are not nailed in place. A muscle in the scrotum and spermatic cord can pull them upward or allow them to drop lower. This movement is especially noticeable when you are cold, nervous, or physically active.
Some teens have what is called a “retractile” testicle, which means a testicle can move up into the groin and then come back down on its own or when gently guided. In many cases this improves with age as the body grows, but it is still worth mentioning to a health care provider.
Undescended Testicles
Before birth, testicles usually travel from the abdomen down into the scrotum. Sometimes one or both do not complete this trip. When a testicle is not in the scrotum by birth or early childhood, it is called an undescended testicle.
Most undescended testicles are treated in early childhood with surgery that moves them into the scrotum. For a teen, the key is knowing whether this has ever been an issue and making sure a doctor has confirmed that both testicles are in the right place.
| Feature | Normally Positioned | Undescended (past early childhood) |
|---|---|---|
| Location | Clearly felt in the scrotum | Missing from scrotum or only partly there |
| Comfort | Usually painless | May be uncomfortable, especially with activity |
| Health concerns | Typical fertility and risk profile | Higher risk of fertility problems and some cancers if not corrected |
| What to do | Routine checkups | Need medical evaluation; often surgery if not already done |
Common Testicle Symptoms and What They May Mean
Many teens worry that every ache or bump is a huge problem. Most of the time, it is not. But paying attention to your body and getting unusual symptoms checked is important. The list below is not for self-diagnosis; it is for knowing when to reach out for help.
- Dull ache or heaviness: Can be related to normal growth, minor injury, or conditions like a varicocele (enlarged veins).
- Sudden strong pain: Could be something serious, like testicular torsion (twisting of the spermatic cord), which is an emergency.
- Swelling or a new lump: Might be from infection, fluid, or (more rarely) a tumor.
- Redness or warmth: May mean infection or inflammation.
- Feeling of “bag of worms” above the testicle: A common description of varicocele, which a doctor should evaluate.
Testicular Torsion: Why Sudden Pain Is an Emergency
Testicular torsion happens when a testicle twists around the spermatic cord, cutting off its blood supply. This can cause rapid, intense pain, swelling, and sometimes nausea or vomiting. It usually affects just one side and often appears suddenly, even during sleep.
Torsion is a medical emergency because the testicle can be permanently damaged if blood flow is not restored quickly. If you ever have sudden, severe testicle pain, go to an emergency department or urgent clinic right away rather than waiting to see if it improves.
Infections and Inflammation
Sometimes the testicles or nearby structures become infected or inflamed. Pain may start gradually, and the area might feel warm or tender. Possible causes include urinary tract infections, sexually transmitted infections, or inflammation of the epididymis.
Only a health professional can sort out what is causing the symptoms. Treatment may involve antibiotics, pain relief, or other care depending on the cause. Ignoring ongoing pain or swelling can make things worse, so it is better to get checked.
Testicular Cancer in Teens and Young Adults
Testicular cancer is uncommon in teens, but it is one of the more frequent cancers in young people with testicles compared to older adults. The good news is that it is often highly treatable, especially when found early.
The most common early sign is a painless lump or swelling in one testicle, or a feeling that one testicle has changed in size or firmness. Most lumps are not cancer, but any new lump should always be examined by a health care provider.
Self-Checks: Getting to Know Your Normal
Learning what your testicles normally feel like can help you notice changes sooner. Picking a regular time, such as once a month, can make self-checks easier to remember. Doing this in a warm shower often helps because the scrotum is more relaxed.
Move each testicle gently between your fingers, feeling for smoothness, shape, and any firm lumps. A soft, squishy structure at the back is usually the epididymis and should not be confused with a lump. If something feels clearly different from usual, that is your cue to see a health professional.
How to Talk to an Adult or Doctor
Bringing up testicle problems can feel embarrassing, but doctors see these issues all the time, and parents or caregivers would rather know than have you suffer in silence. You do not need perfect words; you just need to say enough for someone to understand that something is wrong.
- “One of my testicles has been hurting for a few days.”
- “I felt a lump in my testicle and I am worried about it.”
- “My testicle sometimes goes up into my groin and does not always come down.”
If talking face-to-face feels too hard, you can write it down, send a text to a trusted adult, or tell the nurse at a school or clinic visit. The important part is that someone who can help actually hears about it.
Medical Exams: What to Expect
During an exam, a health care provider will usually ask questions about when symptoms started, what they feel like, and whether anything makes them better or worse. Then they will examine the testicles and scrotum by gently feeling the area with their hands.
Sometimes additional tests are needed, like an ultrasound (a painless scan that uses sound waves) or blood and urine tests. These help the doctor see inside the scrotum and rule out serious problems. You can always ask what each step is for and whether you can have a parent or other trusted adult in the room.
Everyday Care for Testicle Health
There is no special lotion or product needed to keep testicles healthy. Basic hygiene and a few simple habits go a long way. Most of this is common sense, but it helps to think about it directly.
- Wash the genital area gently with warm water and mild soap.
- Wear clean underwear and change it daily.
- Use supportive underwear or athletic gear during sports to protect from injury.
- Avoid very tight clothing that causes pain or numbness.
- Ask a doctor about any ongoing discomfort instead of self-diagnosing.
Emotions, Body Image, and Testicles
It is normal to compare your body to others, especially in locker rooms or online, but testicle size and shape do not determine worth, masculinity, or future sexual ability. Bodies develop at different speeds, and what you see in media is often edited or chosen for unrealistic impact.
If you feel anxious or ashamed about how your genitals look, talking to a trusted adult, doctor, or counselor can help. Honest information and reassurance from professionals are far more reliable than jokes, rumors, or social media comments.
Quick Checklist: When to Get Help Now
Use the list below as a guide. It is not a complete list of every problem, but it highlights some situations where waiting is not a good idea.
- Sudden, severe pain in one or both testicles.
- Painful testicle plus nausea, vomiting, or stomach pain.
- Testicle that used to be in the scrotum but now seems permanently higher up.
- New lump, swelling, or hard spot that was not there before.
- Red, very tender scrotum with fever or feeling very unwell.
FAQs: Your Questions Answered
Is it normal if one testicle is bigger than the other?
Yes. For most people, one testicle is slightly larger or hangs lower. That alone is usually not a sign of a problem. What matters is whether a change happens quickly or is linked to pain, swelling, or a new lump.
My testicles sometimes go up when it is cold. Is that bad?
Not usually. The body naturally pulls the testicles closer when it is cold or when you are nervous. If a testicle seems to stay up or cannot be gently moved back into the scrotum, let a health professional know.
Can testicle injuries affect fertility?
A minor bump or hit that hurts for a short time but then gets better is unlikely to cause serious damage. A strong hit that leads to ongoing pain, swelling, or bruising needs medical attention. Repeated or severe injuries can affect fertility in some cases.
Do I have to tell my parents if I see a doctor about my testicles?
Laws and clinic policies depend on where you live, but in many places teens can talk privately with health providers about sensitive issues. Still, involving a trusted adult can make getting care, transportation, and follow-up easier and less stressful.
Will a doctor think I am weird for asking about this?
No. Health professionals deal with testicle questions and exams all the time. Asking questions and getting checked when something seems wrong shows maturity and responsibility, not weirdness.
Key Takeaways
- Testicles make sperm and testosterone and are meant to sit in the scrotum outside the body.
- Some differences in size, position, and appearance are normal, especially during puberty.
- Sudden severe pain, a new lump, or major swelling should be checked right away.
- Self-checks, good hygiene, and protective gear during sports help support testicle health.
- Talking to a trusted adult or doctor is the best move if anything about your testicles worries you.
