Penile discharge can be either normal or abnormal. It comes from the urethra, but it's not urine. The primary function of the urethra is to eliminate urine that comes from the bladder. It also carries semen from the ejaculatory ducts. The urethra in men follows the length of the penis and is longer than that in women. The tip of the urethra lays on the tip of the penis. Although some discharge in men is natural, other types are a sign of an underlying condition.

General functions of penile discharge are to protect and lubricate the penis. However, when the fluid eliminated doesn't have a purpose or is bothersome, it may be an STD or another medical condition. An abnormal penile discharge may also produce pain, urination difficulties, and irritation. But how do doctors differentiate between a normal and an abnormal penile discharge?

Types of normal penile discharge

There are two categories of normal penile discharge. These are pre-ejaculate and ejaculate. You may experience ejaculate and pre-ejaculate upon sexual stimulation, arousal, or intercourse. Another possibility to experience penile discharge is smegma. However, smegma is not a distinctive type, as it is fluid that accumulates around the head of the penis, and builds up, in time, leading to a highly consistent fluid.

Pre-ejaculate

Men produce pre-ejaculate upon sexual arousal and stimulation. The glands responsible for pre-ejaculate production, called Cowper's glands, lay under the prostate, and they are smaller in size. Pre-ejaculate is thick and alkaline. The following are the primary functions of pre-ejaculate:

  • Pre-ejaculate acts as a lubricant that helps the urethra carry the semen from the ejaculatory ducts, through the tip of the penis
  • Pre-ejaculate lubricates the tip of the penis for easier penetration
  • Its alkaline nature neutralizes the acidity of the lumen of the urethra and the vagina

Although pre-ejaculate and ejaculate come from different structures, scientists found portions of semen in some men's pre-ejaculate. Therefore, there must be a kind of contamination of pre-ejaculate with sperm. We do not know precisely when that happens. Some scientists believe it takes place immediately after ejaculation. Others suggest that leftover sperm from a previous ejaculation contaminates the next pre-ejaculate.

Ejaculate

Ejaculate is the fluid that comes out of the penis with sexual intercourse and, usually, male orgasm. This milky, cloudy fluid also travels through the urethra and towards outside of the body. Upon orgasm, it gains kinetic energy, which helps it move through the lumen of the urethra and to the tip of the penis. The testes, responsible for producing ejaculate, are visible and located under the penis. They are ducts that produce sperm, which then matures in the epididymis and vas deferens.

For semen creation, sperm needs to mix with seminal fluid. Therefore, the consistency of semen is not mainly sperm, as it accounts for an estimated 1% to 5%. The rest are secretions from the bulbourethral glands and prostate, mixed with seminal fluid.

Smegma

Smegma is not a penile discharge, but a build-up of dead cells and moisture around the head of the penis. It may produce a foul smell, but its function is to provide lubrication between the foreskin and penile head. Sometimes, it may attract bacteria. The best way to get rid of smegma is to wash the penis daily, preferably with just water.

Types of abnormal penile discharge

When men experience penile discharge in the lack of sexual stimulation, they might have an underlying medical condition. In this article, we will divide abnormal discharge into STD and non-STD related. The first category includes balanitis, urethritis, trichomoniasis, and urinary tract infections.

Urinary tract infections (UTIs)

UTIs are common bacterial infections that are more prevalent in men than in women. However, when men get a UTI, they may have penile discharge, along with other various symptoms. UTIs usually appear in the lower urinary tract system, and they ascend as time goes by. They may affect the bladder, ureters, and kidneys too. The most common sources of bacteria are the skin and the rectum. Men with a UTI have an altered urine color. It may contain pus and appear cloudy, or blood cells and appear red or pink. Pain and irritability, along with a burning sensation, may accompany urination. Finally, UTIs lead to frequent urination and, sometimes, systemic symptoms, like nausea and vomiting.

Balanitis

Balanitis is an inflammation of the skin around the penile head. Balanitis may be the result of poor hygiene or allergies. Other times, people may get it secondarily to another infection, such as an STD, a bacterial infection, or a dermatological condition. Some skin diseases that may lead to balanitis are psoriasis or eczema. As a result of the inflammation, the head of the penis looks swollen and red. The discharge is thick and white or yellow. Balanitis produces foul smell and may irritate or cause itchiness in the area. Pain or burning sensation upon urination is frequent, as well.

Urethritis

Urethritis refers to the infectious or non-infectious inflammation of the urethra. Sometimes, urethritis appears secondarily to an STI. The penile discharge looks cloudy or white. The most common STI involved is gonorrhea. However, it is not always a condition that produces symptoms. Less frequently, you can have urethritis due to a viral infection, such as HSV or Epstein-Barr virus.

Trichomoniasis

Trichomoniasis is a parasitic infection caused by Trichomonas vaginalis. It produces a thin and white penile discharge. However, approximately only 30% of patients present with symptoms. When symptomatic, trichomoniasis produces frequent urination, painful ejaculation, burning sensation while urinating, and inflammation of the skin and foreskin that covers the head of the penis.

STD-related penile discharge

STIs primarily affect our genitals. You can get an STD through unprotected anal, vaginal, or oral sex. Although many of these infections are asymptomatic in men, they can sometimes present with bothersome signs. If left untreated, they may lead to life-threatening complications. The two most common bacterial STIs that can lead to penile discharge are chlamydia and gonorrhea.

Chlamydia

Chlamydia is the most commonly reported STD in the United States. It is a bacterial infection that spreads with unprotected sex. Men with chlamydia can experience symptoms related to their genitals or oral cavity. The penile discharge in men with chlamydia is white, cloudy, or watery. Additionally, there may be itchiness or burning sensation upon urination. Pain in the testicles may be present, as well.

Gonorrhea

Gonorrhea is another common cause of penile discharge in men. It mostly affects young adults. Although it may cause similar symptoms to those related to chlamydia, the penile discharge caused by gonorrhea is white, yellow, or green. Inflammation of the penile head and swelling of one testicle may be present, as well. Gonorrhea also affects urination, causing irritability and burning sensation.

What should I do if I have penile discharge?

Men with a penile discharge other than pre-ejaculate, ejaculate, or smegma, should consult their doctor for further medical care and information. However, if you recently engaged yourself to unprotected sex, you might need to get tested for STDs. You can do that at home with an STD rapid kit test. Once you get rid of the possibility of having an STI, your doctor will be able to make an easier differential diagnosis.