Mucus in Urine - Should You be Concerned?

Mucus in urine can appear as cloudy urine or white threads at the bottom of the toilet bowl after you pee. It is more frequently present in female urine samples due to cross-contamination from vaginal secretions. Occasional episodes of small amounts of mucus in urine have no clinical significance. However, too much mucus or frequent occurrence could indicate a Urinary Tract Infection (UTI) or another medical condition, which can be evaluated using urinalysis.

What Are Mucus Threads in Urine?

Mucus is the slippery goo-like substance secreted from the body. Most people associate mucus with coughs or colds, but it's normal for a small amount of mucus to appear in the urine. That's because the bladder and urethra contain mucus membranes to help keep the urinary tract moist and protect the urinary tract lining from pathogens. When these membranes produce mucus, it mixes with urine before you go to pee.

However, larger amounts of mucus in the urine can result in visible stringy mucus threads collecting at the bottom of the toilet bowl or pee that looks unusually cloudy.

How To Test Mucus in Urine

A urine test — also called a urinalysis — can help determine the level of mucus in the urine to enable your healthcare provider to decide if there's cause for concern.

A urinalysis involves collecting a sample of pee in a specimen cup, which is then analyzed for the presence of certain cells, bacteria, and other chemicals. Sometimes, a sample is requested first thing in the morning because more concentrated urine is easier to analyze. Urine collection containers and instructions for male and female patients could differ to test mucus in urine.

There are three basic types of urine tests:

• Visual exam. The lab will test the color and clearness of the urine, as well as the presence of any blood and foam, to assess any abnormalities visually.
• Dipstick test. The lab will dip a thin, plastic stick with chemicals into the urine. Test pads on the stick will change color if a certain chemical is present at above-average levels. Please note that a urine dipstick test cannot detect mucus in the urine. However, it is a useful tool to check other urine parameters that could cause mucus threads in urine. They can check for abnormal pH and hydration levels as well as signs of UTI, kidney, and liver diseases.
• Microscopic exam. Laboratory professionals will examine a small amount of urine under a microscope to check for things that can't be seen with the naked eye, like red blood cells, pus cells, bacteria, and mucus levels. A microscopic exam is almost always needed to confirm the presence of mucus in urine.

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In addition to the above tests, your healthcare provider may decide to run other tests to rule out specific conditions or identify the best treatment regimen. If mucus in urine is caused by a urinary tract infection, a urine culture or urine PCR test may be necessary to find specific type of organism causing the infection. To assess kidney function, a urine protein test or albumin-to-creatine ratio test can help you determine the health of your kidneys and whether you have kidney stones.

Urine test strips and other home tests can offer peace of mind if there is mucus present in your urine due to a UTI or protein in the urine. Dipstick tests do not test specifically for mucus in urine but can be used to check other chemical properties of urine that may be causing mucus in your urine. Learn more about these tests here. If you have further questions, contact a healthcare provider.

How To Interpret Your Urine Mucus Lab Results

You'll likely receive a report from the laboratory after they analyze your urine for mucus and other potential signs of illness. Several areas of the report may indicate the presence or absence of mucus.

Laboratory results use four categories to classify the number of mucus threads in urine [8]:

• Rare. Rare mucus in urine means that only trace amounts of this substance are present in the sample.
• Few. It's normal for patients — especially women — to have a small amount of mucus threads in urine.
• Moderate. This amount of mucus may be abnormal and indicate an underlying medical condition.
• Many. A large quantity of mucus threads is unusual and could be a sign of a urinary tract infection, bladder cancer, kidney stones, or other diseases.

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Some labs represent mucus threads in urine using a scale from 1+ to 4+, which corresponds to the categories listed above.

Testing the clarity of your urine is another way that healthcare providers check for mucus.

Laboratories typically use four classifications for urine clarity [9]:

• Clear
• Slightly cloudy
• Cloudy
• Turbid

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Cloudy or turbid urine can be caused by mucus in urine; however, many other factors can contribute to cloudy urine. These may include prostatic, seminal, or vaginal fluids or higher-than-normal concentrations of white blood cells, yeast, phosphates, or carbonates in urine.

The color recorded on the laboratory report can also reveal if you have mucous in your urine. Healthy urine is straw-yellow. By contrast, urine that looks cloudy or milky white may contain mucus. This color can also be a symptom of a urinary tract infection [10].  

Consult your healthcare provider for a more detailed explanation of your urinalysis results. Your physician will review your results in light of other medical tests and assess if the mucus in your urine is benign or caused by a disease that needs treatment.

What Does Mucus in Urine Mean for Your Health?

Too much mucus in urine can be a sign of several medical conditions. Possibilities include:

• Urinary tract infection (UTI): More likely if excess mucus present in urine appears alongside pain when peeing, blood in your pee, a more frequent need to pee, or lower abdominal pain. Learn more about UTI symptoms in this article.
• Chlamydia or Gonorrhea: Sexually transmitted infections (STIs) that may cause watery discharge, which often looks like mucus in urine.
• Kidney stones: Mineral deposits that may pass out of your kidneys and into your urinary tract, prompting your body to produce mucus to expel them.
• Bladder cancer (uncommon): A rare type of cancer called mucinous adenocarcinoma causes excessive mucus to develop in the bladder.

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Large amounts of mucus threads or bloody mucus can be a sign of a urinary tract infection (UTI) or another underlying medical condition.

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