For the most part, you probably think that “penis” and “changing colour” are two terms that should never be in the same sentence. But in some contexts, it's totally normal for your penis to change colour — like, for instance, when you’re aroused, explains Dr. S. Adam Ramin, medical director of Urology Cancer Specialists in Los Angeles. The tip of your penis may turn a deep red or purplish colour before or during sex or while you masturbate, which is caused by the increased blood flow to your penis that helps you get and keep an erection.
But if you’re not in the mood, a colour change down there could be a legit cause for concern. Here are 5 unexpected reasons why your penis could take on an alarming shade of Prince purple, and what you should do about it.
YOU MAY HAVE BRUISED YOUR PENIS.
Bruising happens when an injury causes tiny blood vessels under your skin to leak. That can make your skin turn purple, blue, green, or even black.
Catching your penis in your zipper, getting hit or bumping into something, or just having rough sex are all common causes, says Dr. Jamin Brahmbhatt, a urologic surgeon and co-director of The PUR Clinic. You might be more susceptible if you take blood-thinning medication, which can cause bruising to happen more easily.
The good news? Mild bruises usually don’t hurt much (yup, even on your penis), and they’ll start to fade on their own within a few days, Brahmbhatt says. If that doesn’t happen or if you experience severe pain, call your doc.
YOU MAY HAVE BROKEN YOUR PENIS
Yes, this can happen. Even though your penis doesn’t actually have any bones, it does have ligaments and tissue that can overstretch or even bend. That can lead to intense bruising, swelling, and a deep purple colour, Dr. Brahmbhatt says.
This is most likely to occur during rough sex, since an erection makes your penis less flexible and more prone to bending in a way that it shouldn’t. But penile fractures can also result from intense trauma, like getting severely injured in a car accident.
If your penis is fractured, you’ll likely hear a popping sound followed by a sharp, sudden pain, swelling, and deep discoloration. “In the worst cases, the penis may resemble an eggplant,” says Dr. Brahmbhatt.
The best thing to do is head to the ER right away. Penile fractures usually require surgery, and waiting too long can put you at risk for future difficulty getting erections.
YOU MIGHT BE HAVING AN ALLERGIC REACTION.
“Many types of medications can trigger allergic reactions,” says Dr. Ramin. The most likely culprits are usually antibiotics, pain relievers (like acetaminophen or ibuprofen), and anti-seizure or antipsychotic meds. That can sometimes result in a purplish rash on your skin — including, yup, your penis.
If the rash is accompanied by skin peeling or pain, it could be a condition called Stevens-Johnson syndrome. While Stevens-Johnson syndrome is rare, it affects men twice as often as it does women, and having an autoimmune disorder can also up your risk, says Dr. Ramin.
If you notice a rash after taking medication, call your doctor. He’ll refer you to a dermatologist, who can evaluate the rash and determine whether it’s caused by an allergic reaction.
YOU MIGHT HAVE PURPURA.
Purpura is characterised by small, purple bumps on the skin, often on the penis, buttocks, lower legs, or elbows. The bumps form when the blood vessels under your skin start to leak. The bumps usually aren’t painful, but they can be accompanied by abdominal pain, joint pain, or swelling and pain in the scrotum.
Purpura on the penis is usually the result of an autoimmune reaction that triggers inflammation. “The body’s immune system attacks its own blood vessels, causing the vessels [in the penis] to become inflamed,” Dr. Ramin says. That inflammation is what causes the purple colour.
Luckily, purpura is a lot less scary than it looks. If you see any of these symptoms, call your doctor, who might recommend anti-inflammatory drugs to help clear up the bumps and reduce your discomfort, says Dr. Ramin.
YOU MIGHT HAVE AN STD
If you spot a purple sore on your member, it's possible that the culprit is herpes or syphilis. Herpes sores are more common and usually start out as a blister, which develops into a painful red or purple sore that oozes clear or yellowish fluid. Syphilis can cause red or purple spots that are firm, round, and painless.
Either way, you should see a doctor immediately. When caught early, syphilis can be cured with antibiotics. While you can't get rid of the herpes virus, proper treatment can help you manage outbreaks, and antiviral meds can reduce the pain and help the sores heal.
Avoid sexual contact if you are being treated for a STI, and if you test negative, always practice safe sex regardless.
This article originally appeared on Men's Health