References UK clinical guidance from the NHS, the British HIV Association (BHIVA), and the British Association for Sexual Health and HIV (BASHH). Last updated: April 2026.
Discharge from the penis that isn’t urine, semen, or pre-ejaculate is usually a sign that something needs attention. It doesn’t always mean you have an STI, but it’s one of the most common reasons men visit sexual health clinics, and it’s worth getting checked.
The colour, consistency, and amount of discharge can give clues about what’s causing it. Here’s what different types of penile discharge mean, when to worry, and what to do next.
Concerned about discharge? Get a discreet STI test delivered to your door
What Is Normal Penile Discharge?
Some types of discharge from the penis are completely normal:
- Pre-ejaculate (pre-cum) — clear, slippery fluid produced during arousal. Normal and healthy.
- Semen — white or greyish fluid released during ejaculation. Normal.
- Smegma — a white, waxy buildup under the foreskin in uncircumcised men. Normal but should be cleaned regularly.
Discharge that appears outside of sexual arousal, is coloured (yellow, green, or cloudy), has an unusual smell, or is accompanied by pain, itching, or burning is not normal and may indicate an infection.
What Different Colours of Discharge Mean
| Colour | Possible Cause | Other Symptoms | Action |
|---|---|---|---|
| Clear or watery | Pre-ejaculate (normal), early chlamydia, non-gonococcal urethritis (NGU) | Mild burning when urinating | Test if outside arousal context |
| White or cloudy | Chlamydia, NGU, thrush (candida) | Itching, mild discomfort | Get tested |
| Yellow | Gonorrhoea, chlamydia, trichomoniasis | Pain urinating, swelling, smell | Get tested urgently |
| Green or yellow-green | Gonorrhoea (most likely) | Thick discharge, strong smell, pain | Get tested urgently |
| Bloody or brown-tinged | Urethral injury, prostatitis, rarely cancer | Pain, blood in urine or semen | See GP promptly |
STIs That Cause Penile Discharge
Chlamydia
Chlamydia is the most common bacterial STI in the UK and frequently causes discharge in men. The discharge is typically clear, white, or slightly cloudy, and may be accompanied by a mild burning sensation when urinating. Around 50% of men with chlamydia have no symptoms at all.
Treatment: doxycycline or azithromycin. Read more: What is chlamydia?
Gonorrhoea
Gonorrhoea tends to produce more noticeable discharge than chlamydia. Classic gonorrhoea discharge is thick, yellow or green, and often accompanied by significant pain when urinating. Symptoms usually appear within 1-14 days of exposure.
Treatment: ceftriaxone injection. Read more: What is gonorrhoea?
Non-gonococcal urethritis (NGU)
NGU is inflammation of the urethra caused by something other than gonorrhoea. Chlamydia is the most common cause, but Mycoplasma genitalium, ureaplasma, and other organisms can also be responsible. Discharge is usually mild, clear or white.
Trichomoniasis
Trichomoniasis can cause thin, white discharge, irritation inside the penis, and pain during urination or after ejaculation. It’s less common in men than women and often goes unnoticed. Read more: What is trichomoniasis?
Non-STI Causes of Penile Discharge
Not all discharge is sexually transmitted:
- Urinary tract infection (UTI) — can cause cloudy or slightly discoloured discharge, along with frequent urination and burning
- Thrush (candida) — white, thick discharge with itching, redness, and irritation under the foreskin
- Prostatitis — inflammation of the prostate can cause discharge, pelvic pain, and urinary symptoms
- Balanitis — inflammation of the foreskin/glans, often with discharge, redness, and soreness. Usually caused by poor hygiene or irritation, sometimes by thrush
- Allergic reaction — condom latex, spermicides, soaps, or washing powders can irritate the urethra
When to See a Doctor
See your GP or visit a sexual health clinic if you notice:
- Any discharge from the penis that isn’t pre-ejaculate or semen
- Yellow, green, or foul-smelling discharge
- Pain or burning when urinating
- Blood in your discharge, urine, or semen
- Swelling or pain in the testicles
- Discharge appearing after unprotected sex with a new partner
Don’t wait for symptoms to get worse. Most causes of penile discharge are easily treatable, but untreated STIs can lead to complications. Order a home STI test or find your nearest clinic.
How Penile Discharge Is Diagnosed
Diagnosis usually involves:
- Urine sample — tested for chlamydia, gonorrhoea, and other bacteria
- Urethral swab — a thin swab inserted briefly into the urethra (uncomfortable but quick)
- Visual examination — a doctor can often identify thrush, balanitis, or NGU by appearance
Frequently Asked Questions
Is it normal to have discharge from the penis?
Pre-ejaculate during arousal and semen during ejaculation are normal. Any other discharge, especially if coloured, smelly, or accompanied by pain, should be checked by a healthcare provider.
Can penile discharge go away on its own?
Some mild cases of NGU may resolve, but bacterial STIs like chlamydia and gonorrhoea will not clear without antibiotics. Don’t wait and hope. Get tested.
My discharge is clear. Can it still be an STI?
Yes. Chlamydia and NGU often produce clear or slightly cloudy discharge. The colour alone doesn’t rule out an STI. Testing is the only reliable way to know.
Can I get discharge from oral sex?
Yes. Gonorrhoea and chlamydia can be transmitted to the urethra through oral sex, causing discharge. This can happen when receiving oral sex from someone with a throat infection.
Related reading
- Is Testicular Pain a Sign of an STI?
- What Is a Female (Internal) Condom?
- Cold Sores vs Syphilis Sores: How to Tell the Difference
- Common STI Symptoms in Women
- Do STIs Always Have Symptoms?
Sources
- NHS — Sexual health conditions
- BASHH — UK clinical guidelines for STI management
- British HIV Association (BHIVA) — HIV treatment guidelines
- Terrence Higgins Trust — sexual health information
- UK Health Security Agency — STI surveillance data
Steve Page is a recognised expert on Sexually Transmitted Diseases (STDs) and STD treatments, having published numerous articles in peer-reviewed journals and presented his research at conferences around the world. He has an in-depth understanding of the latest medical research on STDs, and is an advocate for the development of new treatments and protocols to improve the health of those affected. In addition to his research, he has dedicated his career to understanding the causes and symptoms of STDs, as well as how to best treat those impacted.
