Red spot on penis. I used to pull on my penis pretty hard. I was having fun. But this tended to cause some red spots to appear. I was alarmed. Could something be wrong?
A body part, the penis can indicate all sorts of medical problems. But for me, I was just abusing it a bit too much. I needed to masturbate more gently.

Note:Men rely on their penises to function sexually. Often a man becomes concerned if a small spot or bump appears on his penis.

There are many causes of a small red spot or discolored spot on the penis. I will emphasize the worst ones to scare you. But less severe problems are more likely.

Causes include:Excess pressure, tension or overuse, skin disease, sexually transmitted disease, systemic disease, injury.

Petechiae. For healthy men, one common cause of red spots on the penis is petechiae. These are essentially tiny bruises on the surface or near the surface of the penis.

Not harmful:These are not harmful. They are worrisome if you do not know what they are.

Sometimes, small red dots called petechiae and building can occur on the penis but these are not harmful.

Care of People with Diabetes
Petechiae, continued. From the textbook, petechiae tend to occur when the penis has been put under pressure or excess tension. Men sometimes pull too hard.

And:If the penis is used without caution this is likely to occur. The best way to prevent these is to be gentler with the penis.

Anticoagulants:If a man is taking anticoagulant medications, such as for a blood disorder, the penis is more likely to get red spots.

Examples:Some examples of anticoagulant medications include Warfarin (Coumadin) and Sintrom (Acenocoumarol).

[Petechiae] are more likely to occur if the individual is on anticoagulant medicines.Care of People with Diabetes

Lentigo. One common skin disease that can appear on the penis is called lentigo. A lentigo is a spot on the skin with more pigmentation than the surrounding area.

Freckles:These spots are often confused with freckles. They are actually called lentigines.

Note:Lentigines often appear on the penis—they can also appear on the buttocks. We reference the Manual of Dermatologic Therapeutics.

Mucosal lentigines may occur on the lips, vulva and penis. Labial melanotic macules most often appear on the lower lip of young women.

Manual of Dermatologic Therapeutics
Liver or age spots. Lentigines are also called liver or age spots. These terms are actually incorrect, but they are still commonly used. The term "lentigines" is harder to remember.

Sun-exposed:These spots occur in sun-exposed areas, and they are most common in older people.

However:Lentigines can also be found on younger people and in areas not exposed to the sun, such as the penis, vagina and buttocks.

Fair skin:Dark spots (lentigines) tend to occur more often on fair-skinned people, but they can occur on anyone.

Other diseases. Having a dark spot or freckle on your penis could indicate a serious systemic disorder. Mucosal lentigines are associated with system-wide problems.

Note:The Manual of Dematologic Therapeutics states some possible problems. Many of these are serious.

Disorders:These are the Peutz-Jeghers syndrome, the LEOPARD syndrome, and the LAMB syndrome. These are not described here.

Vitiligo. Another reason a spot could appear on a man's penis is vitiligo. This is the opposite of lentigo. It is the loss of skin pigmentation rather than the excess of pigmentation.

Info:Vitiligo often occurs on the penis and scrotum. In fact the male genitalia are often the first place where vitiligo occurs.

Vitiligo and Scrotum
White spot on penis. Let's learn more about white spots on a man's penis. The textbook Vitiligo notes that the glans penis is involved in cases of vitiligo 16.9% of the time.

Tip:The average age of onset for vitiligo on the penis—and other areas—was 29 years old.

But:People developed vitiligo at any age. More men than women get mucosal vitiligo, which involves the genitalia and mouth (page 59).

Vitiligo: Book
STDs. Some sexually transmitted diseases can cause spots to appear on the penis. Many STDs cause other symptoms, such as pain or discharge from the penis.

Syphilis:One STD that is known to cause red spots on the penis is syphilis. This is a serious disease.

The purple necrotic nodule is a rare form of lesion, appearing upon the glans penis or coronary sulcus, as a rule, and begins as a small, dark red spot, becomes roundly convex and is prone to undergo necrotic degeneration.

Western Medical Review, Volume 25, Issue 4
In medicine, a patient history is important. Have you have sexual relations with someone who might have a STD? This could inform diagnosis.
Syphilis. The information from the quotation is about syphilis, which can present with a dark red spot on the penis. Syphilis is not the most common STD. But it does occur.

Cases:There are 36,000 cases of syphilis each year in the United States according to the CDC.

In the United States, health officials reported over 36,000 cases of syphilis in 2006, including 9,756 cases of primary and secondary (P&S) syphilis.

Syphilis: CDC Fact Sheet
Penile cancer. It is time to get worried. Penile cancer is most common in older men, beyond the age of 55. This form of cancer occurs almost only in men who were not circumcised as birth.

Next:I used the book American Medical Association Complete Guide to Men's Health to research this disease (Page 178).

Symptoms of penile cancer include a red spot, crust, wartlike growth, or sore on the penis; discharge from the penis; pain; a lump in the groin; or bleeding during an erection or intercourse.

Complete Guide to Men's Health
Cancer, uncircumcised. If you are older and uncircumcised, and have no other reasons to have a spot on your penis, cancer is a possibility. This problem is less likely in other groups.

Pain, tip:This form of cancer also causes pain in the penis. More scientific penis research is available (scientists love this stuff).

Pain at Tip of the Penis
Injury. An injury can cause a different color spot. The penis has sensitive skin. As with any skin in the body, this can become damaged due to injury.

Burns:Some possibilities include burns, blisters, broken blood vessels and rashes.

Burns and blisters. A burn can occur on the penis. This could be due to an electrical mishap—bathrooms have electrical appliances.

Also:Blisters are possible. Sexual intercourse or masturbation that is vigorous and dry could cause this.

Zipper injury. Once I got my penis stuck in my zipper. I have no plans to do that again. Getting the penis caught in the zipper could cause skin damage or discoloration.Penis Zipper Injury
Broken blood vessels. The penis can be damaged due to overuse. If a man pulls or stretches his penis too much, blood vessels inside the penis can burst.

Red spots:This can cause red spots on the penis. These are broken blood vessels.

Temporary:This effect is also temporary. Broken blood vessels are considered an injury to the penis.

Rash. A rash can occur on the penis. If a substance causes an allergic reaction, small red bumps could occur on the skin of the penis. This would likely cause more than a single red spot.
Story. I have had red spots on my penis. These are small and are most likely a form of petechiae. And for me these were a combination of using a soap I had a skin reaction to.

Tip:Keeping the penile skin clean and free of irritation was helpful to solving the problem.

And:I used a gentler soap and made sure to keep the area clean and free. This was much cheaper than visiting a doctor.

A summary. This page reviewed several possible causes of spots on a man's penis. It is possible to have petechiae, lentigo (dark spots) and also vitiligo (light patches) on the penis.
Sexually transmitted diseases can also cause penis spots. Penis cancer and tissue injuries to the penis cause spots to occur on the penis.