Taking a shower or getting dressed is a normal part of your day. But sometimes, while you are getting ready, you might notice something new and strange on your body. Finding a dark, black or dark red spot on the sack of skin that holds your testicles can be very scary. It is completely normal to feel worried. Your first thought might be that you have a terrible sickness or even skin cancer.

However, you can take a very deep breath and relax. Most of the time, these dark spots are completely harmless. They are not a sign of cancer, and they are not a disease that you can give to anyone else. The most common name for these tiny dark bumps is angiokeratoma. While that is a very big and confusing medical term, it simply refers to a tiny, harmless pool of blood beneath your skin. Learning why these spots appear can help you feel calm and know exactly what to do next.

What’s happening in your body

To understand what these dark spots are, you need to think about how your blood travels. Your body is full of miles and miles of tiny tubes called blood vessels. These tubes act just like water pipes in a house. They carry warm, red blood to every single part of your body, including your skin.

The skin that holds your testicles, which is called the scrotum, is very thin. It has many, many tiny blood pipes running just under the surface. Sometimes, the wall of a tiny pipe gets a little bit weak. When the wall weakens, the pipe stretches and forms a tiny bubble. Blood flows into this tiny bubble and gets trapped there.

Because the trapped blood is sitting still right under the thin skin, it looks like a dark red, blue or even pitch-black spot. According to the National Institutes of Health, an angiokeratoma is simply a widened blood vessel with a thick, slightly rough layer of skin over it. It is not a tumor or a wart. It is just a tiny bubble of trapped blood.

Common causes of black spots on testicles

You might wonder why these tiny blood vessels weaken and form bubbles in the first place. There is no single reason, but it usually comes down to pressure and time.

“Do not fear,” says Dr. Justus Rabach, MD. “The most common reason these dark spots appear is simply getting older. As men age, the skin and blood vessels throughout their bodies naturally lose their strength, tightness and elasticity. When the pipes loosen, they are much more likely to bulge and form tiny blood bubbles.”

Another big cause is gravity and pressure. Blood has to fight gravity to travel from the bottom of your body back up to your heart. Sometimes, the blood pools in the veins of your lower belly and private parts. Sitting in a chair for a very long time every day, or having high blood pressure, can make the blood push hard against the walls of these tiny pipes.

Over time, this pressure causes the pipes to stretch and develop dark spots, explains PubMed Central. You cannot catch these spots from sitting on a dirty toilet seat, nor do you get them from being unclean.

Diagnosis and treatment

If you notice a new black spot, you should have a healthcare provider, specifically a urologist, examine it. These doctors see these harmless dark spots every single day, so you never need to feel shy or embarrassed about showing them.

When you visit, they will usually know exactly what the spot is just by looking at it. They might use a bright light and a small magnifying glass to see the spot clearly. The American Academy of Dermatology Association explains that a healthcare provider looks for specific signs, such as a dark color and a slightly bumpy top, to determine whether it is a harmless blood bubble rather than a dangerous skin mole. They will also gently examine the area to ensure the inside of the testicle feels completely normal and healthy.

Most of the time, the healthcare provider will tell you that no treatment is needed. You can leave the spots alone forever. However, because these spots are full of blood, they can sometimes bleed if you accidentally scratch them or rub them hard against your underwear. If a spot bleeds often, the healthcare provider can easily remove it.

To stop the bleeding, a special hot light, called a laser, can be used to safely close the tiny blood vessel. Sometimes they use a special cold spray to freeze the spot, which dries it out and causes it to fall off like a scab. Both of these simple fixes can be done right in a medical office in just a few minutes.

Is angiokeratoma hereditary?

Usually, these dark spots are not passed down from parents to their children. Most men get them randomly as they grow older. However, there is one very rare exception. The Cleveland Clinic notes a rare inherited disease called Fabry disease. A person is born with Fabry disease because they inherited a broken gene from their parents, which stops the body from breaking down certain fats.

In people with this rare disease, the dark blood spots do not just appear on the private parts. The spots will cover their chest, belly and legs, too. People with this disease will also have other major warning signs, such as severe pain in their hands and feet or difficulty sweating when it is hot outside. If you only have a few dark spots in one private area and feel perfectly fine, it is almost certainly not this rare disease.

What are the risks of angiokeratoma removal?

If you and your healthcare provider decide to remove a spot because it keeps bleeding on your clothes, the fix is very safe. But like any medical fix, there are a few tiny risks you should know about.

The Cleveland Clinic explains that whenever you freeze or burn the skin, it has to heal. The skin on the scrotum is very thin and sensitive. After the healthcare provider removes the dark spot, you might feel a mild burning pain or soreness for a few days. You might also have a tiny amount of bleeding as the scab forms.

The biggest risk is that the skin might heal with a slightly different color. You might be left with a tiny white or light pink scar exactly where the dark spot used to be. For most men, a tiny white scar is much better than a dark spot that keeps bleeding.

When you see a bump on your skin, it is very tempting to squeeze it or try to pop it like a pimple. You must never squeeze or pick at a black spot on your testicles. Because these spots are actually tiny balloons filled with flowing blood, squeezing them will not make them go away. Instead, they will burst open and bleed a lot, which can be very messy and scary. Leave them completely alone and let a healthcare provider safely examine them.

When to see a doctor

Even though these dark blood spots are completely safe, there are some very important times when you must go to a healthcare provider right away. This is the case if a black spot grows very fast, changes shape or develops jagged, uneven edges. You also must see a healthcare provider if the spot hurts terribly, feels hot or leaks yellow liquid, which means germs have gotten inside and caused an infection.

Most importantly, you must feel the difference between the skin and what is inside. If you feel a hard rock or a solid lump deep inside the actual testicle, not just floating on the skin, you must go to the healthcare provider immediately. A hard lump inside the testicle can be a sign of a serious problem like cancer.

“When a man sees a black spot on his private area, his first thought is often very scary. But I tell my patients every day that these tiny dark bumps are almost always just harmless collections of blood, not cancer. It is always smart to get any new skin change checked, but there is rarely a reason to worry,” says Dr. Sylvia Hsu, a dermatologist in Philadelphia, Pennsylvania.

Bottom line

Black spots on the testicles are usually harmless, tiny bubbles of trapped blood called angiokeratomas. They happen as men get older or from pressure in the blood vessels, and they do not need to be treated unless they start bleeding and bother you. While these skin spots are generally harmless, you should always have a healthcare provider examine any new bump to ensure it is not a sign of a deeper, more serious problem.

Frequently Asked Questions

How many men have angiokeratoma?

These dark blood spots are incredibly common, and studies show that many older men will develop at least a few during their lifetimes.

How big can an angiokeratoma get?

Most of these harmless spots stay very small, usually no bigger than a tiny pinhead or the tip of a crayon.

What type of healthcare provider treats angiokeratoma?

A healthcare provider who specializes in men’s private parts and urinary systems, called a urologist, or one who treats the skin, called a dermatologist, can easily examine and treat these spots.

Citations

Ivy H, Julian CA. Angiokeratoma Circumscriptum. PubMed. Published 2023. https://www.ncbi.nlm.nih.gov/books/NBK549769/

Adams NT, Paterson C, Poles J, Higgins S, Stoner L. The Effect of Sitting Duration on Peripheral Blood Pressure Responses to Prolonged Sitting, With and Without Interruption: A Systematic Review and Meta-Analysis. Sports Medicine. Published online September 8, 2023. doi:https://doi.org/10.1007/s40279-023-01915-z

American Academy of Dermatology Association. Melanoma: Signs and symptoms. www.aad.org. https://www.aad.org/public/diseases/skin-cancer/types/common/melanoma/symptoms

Cleveland Clinic. Fabry Disease. Cleveland Clinic. Published August 21, 2023. https://my.clevelandclinic.org/health/diseases/16235-fabry-disease

Cleveland Clinic. First Aid for First-, Second- and Third-Degree Burns. Cleveland Clinic. Published March 4, 2025. https://health.clevelandclinic.org/how-to-treat-a-burn