Why Is There Mucus in My Urine?

By Zina Semenovskaya, MD
Medically reviewed checkmarkMedically reviewed
September 6, 2022

If you have ever gone to the bathroom and noticed a clear, white, or off-white slimy substance mixed in with your urine, this is mucus. Mucus in your urine looks thin and fluid-like, and is usually not something to be too concerned about—small amounts of mucus are necessary for your overall health.

However, in some circumstances, excess mucus in your urine could be a sign of a more serious health condition that requires medical evaluation. 

In this article, I’ll talk about when this discharge is normal, and when mucus in your urine could be a sign of a more serious condition, like a urinary tract infection, irritable bowel syndrome, sexually transmitted infections, ulcerative colitis, or kidney stones.

I’ll also tell you whether mucus in your urine could be a sign of bladder cancer. I’ll outline some of the ways doctors test the mucus in your urine, and tell you when to see a doctor.

Regular Discharge

Normal vaginal discharge is a common cause of mucus in urine. For women, a small to moderate  amount of vaginal discharge is completely natural.

In fact, it serves an important cleansing function in the female reproductive system, preventing harmful bacteria from entering and spreading throughout the body.

Small glands located in the vagina and cervix secrete fluid that helps wash away dead cells and bacteria to keep it clean.

This discharge may have a subtle scent, but is usually not unpleasant. The color and density of the discharge will change throughout a menstrual cycle, especially during ovulation and menstruation.

Vaginal discharge also produces lubrication during sexual intercourse.

When sexually aroused, a vagina may produce more discharge than normal that is thick and creamy in texture. This helps prepare the body for pleasure, and also cleanses it after sex.

Unfortunately, the amount the body produces decreases with age, and is significantly less after menopause. The color and smell of your vaginal discharge can be a sign that you are healthy, or in some cases, it can indicate an infection.

If you notice changes in your vaginal discharge that are not related to your menstrual cycle, speak with a healthcare provider.

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If you’re experiencing an unpleasant odor, you can gently cleanse the vaginal area with warm water and a non-fragranced soap.

If you suspect that you have a yeast infection, you can treat this with over-the-counter antifungal medications, which will reduce the itching and associated discharge. 

Urinary Tract Infection (UTI)

A burning sensation when you pee paired with a frequent urge to pee is a sign that you may have a urinary tract infection (UTI).

You may rush to the bathroom only to discover that you cannot squeeze a drop out—or when you do, you may notice that your urine is cloudy, dark, bloody, or strange-smelling, and there may be an abnormal amount of mucus mixed in.

A UTI occurs when bacteria, often from the skin or rectum, enters the urethra and infect various points along the urinary tract.

A urinary tract infection is a common cause of a bladder infection (cystitis), and a less common cause of a kidney infection (pyelonephritis).

UTIs are very common, especially in people with vaginas—50-60% of women have at least one UTI in their lifetime. For every eight people with vaginas who get a UTI, one person with a penis will get one.

Urinary tract infections in people with penises are always considered complex infections, and require further testing.


If you suspect you have a UTI, drink plenty of water. Staying well hydrated can also help prevent urinary tract infections.

Your doctor may also prescribe you antibiotics, the most common treatment for UTIs.

Continue taking the antibiotic as prescribed, regardless of whether you notice improvement, to ensure the efficacy of the medication. Those struggling with low back pain or cramping should consider a heating pad applied to the area to help soothe discomfort.

One prevention method for those struggling with recurring UTIs is drinking cranberry juice. It has been argued that the red berry contains a tannin that might prevent E. coli bacteria from sticking to the walls of your bladder, thus preventing infection.

Sexually Transmitted Infections (STIs) 

A change in discharge accompanied by a host of symptoms including painful urination, and lower back pain are signs of a sexually transmitted infection (STI).

People with penises might experience testicular pain, while people with vaginas may notice vaginal bleeding and find sexual intercourse painful.

Both chlamydia and gonorrhea are bacterial infections of your genital tract that can cause abnormal discharge, including the presence of mucus in your urine.

Chlamydia is often referred to as a silent infection, because many who have it show no symptoms, making it difficult to diagnose and treat. Symptoms of gonorrhea are generally more obvious than chlamydia. This infection can also grow in your mouth, throat, eyes, and anus.

Within 10 days of exposure, you may notice symptoms such as a thick, cloudy, or bloody discharge from the penis or vagina. It is common for people with penises to experience swollen, painful testicles, and women to have heavy menstrual bleeding or bleeding between periods. 


Since chlamydia and gonorrhea are bacterial infections, they are treated with antibiotics. For chlamydia, azithromycin is usually prescribed in a single, large dose. In some cases, your doctor may prescribe doxycycline, which is taken twice per day orally for approximately a week.

As recommended by the Centers for Disease Control and Prevention (CDC), the most effective treatment for gonorrhea is a single dose of 500 mg of intramuscular ceftriaxone.

Irritable Bowel Syndrome (IBS)

Bloating, diarrhea, gas, constipation, and abdominal pain are all common symptoms of irritable bowel syndrome (IBS). Another possible symptom of IBS that can occur is mucus in the digestive tract.

This mucus comes from the large intestine or colon. After leaving the body through the anus, the mucus can attach to your stool and mix in with urine.

People with IBS who experience this may have a hard time pinpointing where the mucus comes from, and can mistake the excess fluid as secreting from their urinary tract. 


There is no cure for IBS, but there are several treatment options that effectively alleviate symptoms. The right treatment for you will depend on identifying what is causing your IBS and what symptoms are most affecting you.

Fiber supplements such as psyllium (Metamucil), taken with lots of fluids, may help control constipation. Over-the-counter (OTC) laxatives may also be recommended.

Loperamide (Imodium A-D) is an anti-diarrheal medication that can help control diarrhea. Additionally, your doctor might prescribe a bile acid binder, such as cholestyramine (Prevalite), colestipol (Colestid), or colesevelam (Welchol).

Where stress and anxiety are the cause of IBS, antidepressants may be prescribed by your doctor.

Ulcerative Colitis 

Ulcerative colitis, an inflammatory bowel disease (IBD), causes Inflammation and ulcers (sores) in your digestive tract. Ulcerative colitis affects the innermost lining of your large intestine (colon) and rectum, causing irritation and inflammation.

Symptoms generally develop gradually, and some important signs include a stomach ache or diarrhea with blood or pus in it. Your body may produce excess mucus as a result of the inflammation of the colon.

This can mix in the toilet and easily be mistaken for mucus in your urine. 


Depending on the severity of your condition, drug therapy and surgery are the treatment options for ulcerative colitis. Anti-inflammatory drugs are often the first step in the treatment plan, while immune system suppressors suppress the immune system response that begins the process of inflammation.

Your healthcare provider may prescribe biologics, which target levels of protein made by the immune system. In more severe cases where drugs may not be effective, surgery might be required.

This procedure, known as ileoanal anastomosis (J-pouch) surgery, involves removing your entire colon and rectum (proctocolectomy).

Your surgeon constructs a pouch from the end of your small intestine, which is then attached directly to your anus, eliminating the need to wear a bag to collect a stool.

If you think that you may have ulcerative colitis or Crohn’s disease, another type of inflammatory bowel disease, please see your doctor right away.

Kidney Stones 

Hard crystals formed from minerals and salts in your kidneys create a medical condition known as kidney stones (also called renal calculi, nephrolithiasis, or urolithiasis).

They can affect any part of your urinary tract—from your kidney to your bladder—and occur when urine collects and becomes concentrated.

The minerals crystallize and stick together.

Kidney stones are often the result of poor diet, excess body weight, some medical conditions, and certain supplements and medications.


It can be incredibly painful to pass kidney stones, but they can be passed most of the time by drinking plenty of water, and do not require invasive treatment.

Pain relievers such as ibuprofen (Advil, Motrin IB, others) or naproxen sodium (Aleve) can help with managing discomfort for a few days, but should not be taken long term.

In more severe cases, your doctor may prescribe alpha-blockers such as tamsulosin (Flomax) and the drug combination dutasteride and tamsulosin (Jalyn) to help pass your kidney stone, though how effective they are is still uncertain.

Alpha-blockers relax the muscles in your ureter. This helps you pass the kidney stone more quickly and with less pain. If you think that you are passing a kidney stone and the pain is not improving after 1-2 days, see your doctor for further evaluation. 

Is Mucus in Urine a Sign of Bladder Cancer?  

Bladder cancer can cause urinary changes such as a burning sensation when you pee, or having to urinate more often.

Blood in the urine is another sign. In rare cases, a person with bladder cancer may have mucus in their urine. If mucus in urine is a sign of cancer, it is usually accompanied by other symptoms such as blood in urine, weight loss, lower back pain, bone pain, or swollen feet. These are signs of advanced bladder cancer.

Testing for Mucus in Urine

A urinalysis test, which is a collected urine sample examined under a microscope, can determine if there is too much mucus in your urine by doing a visual check of your urine, testing for certain chemicals, and looking for certain types of cells.

This can be done during a regular check-up. 

Your doctor may request a urinalysis if you have signs of a UTI, including any of the following symptoms:

  • Frequent urge to urinate, even when you have little urine in your bladder
  • Painful urination
  • Dark, cloudy, or reddish-colored urine
  • Bad smelling urine
  • Weakness
  • Fatigue

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When to See a Medical Professional

While small amounts of mucus in your urine are completely natural, a large amount or frequent mucus in your urine can be signs of a more serious underlying condition.

If you notice these, visit a healthcare provider for a checkup.

Most causes of mucus in the urine are easily treatable with medication, dietary changes, or other appropriate interventions, but in the event that the underlying cause is left untreated, this can lead to more serious health complications.

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Frequently Asked Questions

What are the risks of having mucus threads in my urine?
Mucus travels along your urinary tract to help flush out germs that can cause infections. Having mucus threads in your urine occasionally is completely natural, as the body is helping to expel anything that could cause a threat to your health. Large amounts of mucus threads in your urine, however, could be a sign of a kidney infection, STI, kidney stones, or other health issues.
Is it normal for mucus to be in urine when you have a cold?
No. When you have a cold, it is normal for you to have excess mucus in your nasal passages and your throat, but not common for your body to expel excess mucus in your urine. Mucus in your urine is usually related to an infection in your urinary tract or lower abdominal area.
What causes white strings in your urine?
UTIs are a common cause of white strings in your urine. Additional causes include kidney stones, STIs, kidney stones, and kidney infections. If you are unsure about the fluid-like discharge, speak with your healthcare provider, who can help determine the cause.
K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

Zina Semenovskaya, MD

Dr. Semenovskaya specializes in emergency medicine, and received her medical degree from Weill Cornell Medical College. She is currently the medical director at Remote Emergency Medicine Consulting, LLC and splits her time working clinically as an emergency medicine attending in California and Alaska. She is the first of our doctors to be fluent in Russian.

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