Mucus in Urine: Is It Normal and When Does It Matter?

Usually, yes. MedlinePlus says a normal urine test result usually shows a small or moderate amount of mucus, and the US National Library of Medicine notes that cells lining the urinary tract produce a small amount. A large amount may be a sign of an infection or another condition, and may lead to further tests.

On its own, a mucus result rarely answers a question. Clinicians read it alongside symptoms and the other parts of the urinalysis, such as white blood cells, nitrites, blood and the types of cells seen. This guide helps you understand the finding and what to ask; it cannot interpret your own result.

Mucus by itself is not a reason for emergency care. The symptoms that may come with it can be. The NHS advises an urgent GP appointment or help from NHS 111 in the situations below, and calling 999 or going to A&E if someone is confused, drowsy or having difficulty speaking. Outside the UK, use your local urgent or emergency services.

• Urinary symptoms with a high temperature, feeling hot or cold and shivery, or a very low temperature.
• Pain in the lower tummy or in the back just under the ribs, which the NHS notes could be a sign of kidney infection.
• Blood in your pee.
• Symptoms that get worse quickly or do not improve within 48 hours of treatment.
• Urinary symptoms if you are pregnant, a man, have diabetes, use a catheter or have a weakened immune system.

Mucus is a thick, slippery fluid that coats and moistens parts of the body. The US National Library of Medicine's MedGen entry explains that a small amount is produced by cells lining the urinary tract, so some mucus in a urine sample is expected.

Mucus is reported from the microscopic part of a urinalysis, where a laboratory looks at the urine sediment for cells, crystals, casts, bacteria and mucus. Laboratories report it in different ways, and reporting styles differ between laboratories, so check the wording and any range printed on your own report.

Yes. MedGen lists contamination of the sample before testing as one possible explanation for increased mucus. Material from the skin around the genitals, or vaginal discharge, can get into the container while the sample is collected. Cleveland Clinic notes that vaginal discharge and menstrual blood can interfere with some urinalysis results.

A clue can come from elsewhere on the same report. Cleveland Clinic explains that squamous epithelial cells in urine probably mean the sample picked up cells from another part of the body; our guide to squamous epithelial cells in urine covers this in more detail. If contamination is suspected, a clinician may ask for a repeat sample.

A careful collection reduces the chance of a misleading result. MedlinePlus describes the clean-catch method in these steps. Follow any different instructions from your own clinic or laboratory.

• Wash and dry your hands, and open the container without touching the inside.
• Clean the genital area with the wipe provided: separate the labia and wipe from front to back, or wipe the head of the penis, pulling back the foreskin first if you have one.
• Start peeing into the toilet for a few seconds, then stop.
• Collect the middle part of the stream in the container, then finish in the toilet.
• Close the container and return it as instructed. The American Academy of Family Physicians notes that delays of more than two hours before examination often make results unreliable.

MedlinePlus lists conditions that can be linked with a large amount of mucus in urine. These are possibilities a clinician may think about, not a diagnosis, and most need other findings or tests before they are considered:

• A urinary tract infection (UTI).
• A sexually transmitted infection (STI).
• Kidney stones.
• Irritable bowel syndrome (IBS).
• Bladder cancer, which is a less common explanation and is not diagnosed from mucus alone.

It matters most when it sits alongside symptoms or other abnormal results. Cleveland Clinic explains that more white blood cells than usual can point to infection or inflammation in the urinary tract, and that a positive nitrite test can mean a UTI. Our guide to leukocytes in urine explains what a white blood cell result can and cannot show.

Cleveland Clinic also notes that clinicians rarely use urinalysis alone to diagnose a condition, and that an abnormal result does not necessarily mean a medical condition. Depending on the whole picture, next steps might include a repeat sample, a urine culture or tests for an STI. MedGen also notes that people who have had urinary tract reconstruction using a piece of bowel can have increased mucus, so tell the clinician about any past urinary surgery.

Bring the full urinalysis report, including the microscopy section, and note any symptoms with the dates they started.

• How much mucus was reported, and is that amount usual for a sample like mine?
• Do the other results, such as white cells, nitrites, blood or squamous epithelial cells, change how you read it?
• Could the sample have been contaminated, and should I repeat it with a clean catch?
• Is a urine culture, an STI test or any other test needed?
• Which symptoms should make me seek help before any follow-up?

On SameCase, patients and verified doctors share de-identified cases. Seeing how others described a urinalysis that mentioned mucus, and which questions came up in their follow-up, can help you prepare your own list. These cases cannot explain your result or replace a review by your own clinician.