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Why Does My Penis Smell Fishy? Seven Causes and Possible Treatments 

Like your armpits and feet, your groin area may give off unpleasant odors, especially after a workout or long day at work. However, if your penis smells fishy, it may indicate improper hygiene or an underlying health issue. This guide takes an in-depth look at the causes of penile odor and effective treatments. 

Penis Smell Fishy? 7 Possible Causes 


Smegma is the accumulation of dead skin cells and oily secretions under the foreskin of uncircumcised men. It may appear thick and cheesy. However, without regular cleaning, smegma becomes a bacterial breeding ground. These bacteria produce a foul odor and may even inflame the foreskin. 

How to Get Rid of Smegma 

The sebaceous glands and skin consistently produce smegma, which is a good thing as it is a natural, healthy lubricant. However, smegma older than 24 hours is susceptible to bacterial growth, especially in a warm and sweaty environment. To prevent a fishy odor, wash the area under the foreskin at least once per day, using a mild soap and warm water. 

When to See a Doctor 

Consult with your doctor if the smegma hardens, causes itchiness, or results in inflammation of the penis glans or foreskin. 


Gonorrhea is a sexually transmitted infection of the Neisseria gonorrhoeae bacterium. This infection transmits through sexual intercourse without a condom, and it targets moist and warm areas of the body, including the penis. 

Gonorrhea Symptoms 

The symptoms of gonorrhea typically develop within two weeks after infection. Gonorrheal symptoms affecting the penis include:

  • White, yellow, or light brown penile discharge
  • An increase in urination frequency
  • Redness, pain, and swelling around the penile opening
  • A smelly penis
  • Testicle pain or swelling

Gonorrhea can also cause itching in the groin area. Usually, symptoms remain for several weeks after you receive treatment. 

Gonorrhea Testing and Treatment 

If you don’t receive treatment for gonorrhea, it can result in permanent health issues, including epididymitis and infertility. If you are sexually active, regular gonorrhea testing will allow you to seek early treatment. 


Chlamydia is a sexually transmitted infection by the chlamydia trachomatis. This infection spreads through unprotected sexual contact or by sharing a sex toy with someone who has the infection. 

Chlamydia Symptoms 

In most cases, chlamydia doesn’t cause any symptoms. However, if you have a chlamydial infection, you may experience late-onset symptoms, including:

  • A white or watery penile discharge
  • Pain when urinating
  • Painful or swelling testicles
  • The emission of unpleasant odors

Chlamydia is one of the STDs that can cause itching. If you experience any of the above symptoms, you need immediate treatment. 

Chlamydia Testing and Treatment 

If you had unprotected sexual intercourse or are worried that you may have chlamydia, schedule same-day STD testing. Your doctor will likely treat chlamydia with a short antibiotic course.

Urinary Tract Infection (UTI) 

A urinary tract infection is when bacteria cause infection and inflammation in the urethra or bladder. In most cases, the bacteria causing the infection are E. coli, which usually live in the intestines. 

UTI Symptoms 

In men, common symptoms of a urinary tract infection include:

  • A fishy odor emitting from the penis glans
  • A burning sensation or pain during urination
  • Pink or cloudy urine

Uncircumcised men have a higher risk of contracting a urinary tract infection. 

UTI Diagnosis and Treatment 

If you experience any of the above symptoms, schedule an appointment with your doctor. After a physical examination and diagnosis, your doctor will likely prescribe antibiotics, such as nitrofurantoin, cephalexin, or Fosfomycin.  

Yeast Infection 

A penile yeast infection is a condition that mainly affects uncircumcised men. The Candida fungus triggers this condition, and its most common symptom is an unpleasant smell radiating from the affected area.

Other Symptoms of a Yeast Infection 

A fishy odor is not the only symptom of a yeast infection. Men who suffer from a penile yeast infection may also experience:

  • Burning or itching sensations
  • Redness, pain, and swelling
  • The accumulation of a thick, white substance around the glans
  • Pain or irritation when urinating 

Diagnosis and Treatment 

A medical diagnosis is necessary to establish the presence of a yeast infection. Your doctor will likely recommend medication, such as Diflucan, to kill the fungus. 

Non-Gonococcal Urethritis (NGU) 

Non-gonococcal urethritis is a urethral infection that is not the result of gonorrhea. Possible causes of NGU include trauma to the urethra, a sexually transmitted infection, or a urinary tract infection. In most cases, NGU causes a fishy smell around the groin area. 

Other Symptoms of an NGU Infection 

Other symptoms of urethritis include:

  • A cloudy or white penile discharge
  • Pain or a burning sensation during urination
  • Irritation or soreness around the penis tip

NGU only causes symptoms in men. Women with urethritis are generally asymptomatic. 

NGU Treatment 

A 10-panel STD test is typically necessary to determine the presence of NGU. A course of antibiotics is necessary to treat this condition effectively. 

Balanitis (Swelling of the Foreskin) 

Balanitis is a condition presenting as swelling of the foreskin or head of the penis. Common causes of this balanitis include a chronic skin condition or infection. Even though this inflammation is not severe, it can be painful. 

Common Symptoms of Balanitis 

Common balanitis symptoms include:

  • An unpleasant penis odor
  • Tightening or swelling of the foreskin
  • Swelling of the penis head
  • Penile discharge
  • An itching penis
  • Painful or burning skin

As the penis head swells, it can cause pain during urination. 

Diagnosis and Treatment 

Diagnosing balanitis requires a physical examination. Treatments involve the prescription of anti-itch, antifungal, or antibiotic medication. An over-the-counter product, such as antifungal cream, can also alleviate balanitis. 

Penile Hygiene Tips 

Proper penile hygiene can prevent infections and the build-up of bacteria, causing a fishy smell. Practical hygiene tips you can follow include:

  • Pulling your foreskin back when urinating
  • Washing your penis underneath the foreskin using warm, soapy water
  • Gently and properly drying your penis after showering using a patting motion
  • Wearing loose-fitting cotton underwear
  • Wearing condoms during sexual intercourse to prevent an STI
  • Washing your penis after intercourse to remove bacteria that can cause an infection
  • Using a water-based lubricant instead of saliva or an oil-based product

If you suspect that you have an infection, schedule a rapid STD test to start treatment early. 

Prevention Is Better Than Cure 

Why does my penis smell fishy? If you maintain proper hygiene but still ask this question, you need to see a physician. In most cases, the causes of an unpleasant penile odor are not severe, but they can potentially lead to serious health concerns.

At Rapid STD Testing, we offer fast and discreet STD testing with results within one to three business days. If you suspect that you may have a sexually transmitted infection, go on our site to find a lab near you, call us, and schedule a same-day STD test.