- A swollen penis that does not go away within a few minutes may be a sign of infection, allergy, or penile fracture.
- Pain, redness, itching, sores, discharge, bleeding, or trouble urinating along with swelling should be assessed by a doctor.
- Sudden swelling with severe pain, bruising, bleeding, or immediate loss of erection needs urgent medical attention.
A swollen penis is common after sex or masturbation due to increased blood flow and usually goes away within a few minutes. However, a swollen penis that does not improve may be linked to conditions like infections, allergic reactions, or even a penile fracture.
A swollen penis caused by a medical condition is often accompanied by symptoms such as pain, redness, itching, sores, discharge, or bleeding. Common causes include balanitis, genital herpes, urethritis, and skin irritation from products or fabrics.
Persistent swelling or severe symptoms may require treatment with medications like antifungals, antibiotics, or antivirals, depending on the cause. In more serious cases, such as penile fracture or lymphedema, urgent medical care or surgical treatment may be needed.
Why is my penis swollen?
In most cases, a swollen penis is normal and resolves within a few minutes. It can happen following sex or masturbation, due to increased blood flow to the genital area. Other causes can include:
1. Balanitis
Balanitis is inflammation of the glans (head) of the penis. When the foreskin is also inflamed, the condition is called balanoposthitis.
It typically causes redness, itching, warmth, and swelling, and is most often due to a fungal infection such as Candida albicans, though it can also result from bacterial infection, allergic or irritant reactions, or inadequate hygiene.
How to treat: If you experience any signs of infection, consult a healthcare provider for evaluation and appropriate treatment. Fungal balanitis is typically managed with antifungal medication, while bacterial balanitis may require antibiotics.
According to the NHS, washing the penis daily and avoiding soap or other irritants can help manage and prevent balanitis.
2. Allergic reaction
Penile swelling can result from an allergic reaction or irritation caused by factors such as unclean underwear, certain fabric materials, lubricants, body washes, or condoms. Along with swelling, the irritation may also lead to itching, redness, or blisters on the penis.
How to treat: It’s important to identify the substance that triggers your allergy and avoid any contact with it whenever possible. Keep the genital area clean by using mild soap and wearing breathable cotton underwear to help prevent penis irritation.
3. Fracture
A penile fracture typically occurs during sexual activity when the penis is forcefully and suddenly bent. Although the penis contains no bone, the injury is called a “fracture” because it involves a tear in the membrane surrounding the corpus cavernosum.
This condition usually causes sudden pain, immediate loss of erection, bruising, swelling, and sometimes bleeding.
How to treat: If you suspect a penile fracture, seek immediate medical attention. A doctor will evaluate the injury and determine whether surgical repair is necessary.
In some minor cases, conservative treatment with medication may be appropriate, including applying ice to the area and avoiding sexual activity for about six weeks. A healthcare provider may also prescribe medication to reduce nocturnal (nighttime) erections during recovery.
4. Genital herpes
Genital herpes is a sexually transmitted infection (STI) that usually begins with small blisters or sores in the genital area, often on the penis. These blisters may break and turn into painful ulcers and can be accompanied by itching, pain, burning when urinating, general discomfort, and sometimes swelling. Read more about the symptoms of genital herpes and how they are managed.
How to treat: It is important to see a healthcare provider to confirm the diagnosis and begin appropriate treatment, which typically includes antiviral medications taken by mouth or applied directly to the skin.
According to the CDC, antiviral medications are used to treat or prevent symptomatic genital herpes recurrences, and correct, consistent condom use (every time you have sex) can reduce the risk of transmission.
5. Urethritis
Urethritis is an inflammation of the urethra caused by bacteria such as Chlamydia trachomatis or Neisseria gonorrhoeae. Common symptoms include swelling of the penile shaft, itching, testicular swelling, pain or difficulty when urinating, and penile discharge.
How to treat: It is important to see a healthcare provider to begin treatment, which usually includes antibiotics such as ciprofloxacin or azithromycin. Be sure to take all medications exactly as prescribed to ensure the infection is fully treated.
6. Lymphedema
Lymphedema occurs when lymphatic fluid builds up abnormally in the body. This can happen for several reasons, including congenital issues or blockage of the lymphatic system. In rare cases, lymphatic fluid may accumulate in the penis or scrotum after a skin infection, causing swelling, discomfort, and redness.
How to treat: Sudden swelling of the penis accompanied by pain and redness should be evaluated right away by a doctor or in a hospital.
If the cause is an infection, treatment with oral or intravenous (IV) antibiotics may be needed. In severe cases where fluid buildup is significant, surgical drainage may be required to relieve the swelling.
How to prevent
You can help prevent a swollen penis by maintaining good hygiene. Using condoms during sex reduces the risk of sexually transmitted infections (STIs), and applying enough lubricant can help prevent irritation.
Wearing cotton underwear is also recommended for comfort and to reduce friction. If you notice any new symptoms or changes in the genital area, it’s important to see a doctor for evaluation.