Having a veiny penis usually isn’t a cause for concern, but men should always contact their doctor if they are experiencing pain, swelling, or other alarming symptoms.

Blood vessels are an integral part of penile anatomy. When a man has an erection, his arteries expand to allow more blood to flow and then be trapped into the penis. The trapped blood makes the penis firm, giving him the rigidity he needs for intercourse.

After a man ejaculates (or if sexual stimulation stops), veins carry the blood out of the penis, which then returns to a flaccid (not erect) state.

There are several veins and arteries that carry blood to and from the spongy erectile tissue in the penis. Veins may look larger than usual during and immediately following an erection. Although the appearance of prominent veins may cause alarm, they indicate healthy blood flow.

Genetics and age can influence skin thickness, which may make veins appear more prominent or bigger than usual. Also, blood clots and other conditions that affect the cardiovascular system can trap blood in the veins, which may affect how these blood vessels look.

The size of your veins has no impact on your ability to get or maintain an erection. Vein size doesn’t affect the strength or volume of your ejaculation, either.

Some conditions that impede blood flow, such as blood clots, can affect vein size and have some effects on erectile function.

Vein size and visibility may vary over a person’s lifetime. They can also change as a result of sexual activity, or due to an underlying health condition.

Erection – During an erection, oxygenated blood from the heart flows through the cavernous artery, which supplies the three chambers of spongy tissue that make up the corpus cavernosum and the corpus spongiosum.

The increase in blood flow causes the spongy tissue to expand, resulting in an erection. The tunica albuginea keeps blood in the corpus cavernosum. The blood will then drain through the veins near the surface of the penis and travel back to the heart and lungs. The spongy tissue will remain engorged with blood until the erection goes away.

Varicocele – A varicocele refers to enlargement of the veins that make up the pampiniform plexus in the scrotum, which is the loose skin that surrounds the testes.

Blood clots – A blood clot, or thrombosis, is a medical condition that occurs when blood cells stick together to form solid masses in the blood vessels. Blood clots can interrupt or completely stop blood flow.

Lymphedema – Lymphedema refers to swelling that occurs when lymph fluid incorrectly flows through the body.

Peyronie’s disease – Peyronie’s disease occurs when scar tissue, or plaque, forms in the top or bottom of the penis. The buildup of scar tissue can cause the penis to curve or bend, which can lead to severe pain during sexual intercourse.

Most of the time, there’s no need to worry if your penis veins look more pronounced than usual. But if the appearance of your veins if causing you distress, talk with your doctor. They can assess your symptoms and diagnose any underlying issues.

People should seek immediate medical attention if they experience :

• painful erection or ejaculation
• swelling or lumps on the penis or scrotum
• pain in the lower back or abdomen
• unusual discharge from the penis