Foamy pee may be a sign of proteinuria, a condition in which protein concentrations in the urine are high, typically due to a kidney-related issue. There may also be harmless explanations for bubbly or foamy pee, such as dehydration, and potentially severe ones, like preeclampsia or diabetic kidney disease.
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Benign Causes of Foamy Urine
While foamy pee may worry you if it happens suddenly or for no known reason, there are some harmless reasons for this occurring, including:
- Cleaning products: Toilet cleaners containing surfactants like sodium laureth sulfate (SLES) can leave a residue on surfaces and in the water that causes foaming when you pee.
- Dehydration: The lack of water in urine causes high concentrations of a waste product called urochrome. Urochrome has surfactant properties (similar to soap) that can cause your urine to foam up when you pee.
- Rapid urine stream: A strong urine stream can create temporary bubbles or foam even if there is relatively little urochrome in your urine.
- Stress: Psychological and physical stress (including high temperature, fever, and vigorous exercise) can temporarily affect how the kidneys work and cause a harmless increase in urinary protein.
Proteinuria As a Cause of Foamy Urine
Proteinuria, also known as albuminuria, describes excess protein in the urine. In healthy people, the kidneys release little protein—only around 150 milligrams (mg) per day. Amounts higher than this may indicate a health problem.
There are two broad reasons why this might occur: either the filtering units of the kidneys are damaged, allowing proteins to escape (glomerular proteinuria), or you have excessive amounts of protein in your blood that exceeds the reabsorption rate of the kidneys (overflow proteinuria).
Causes of glomerular proteinuria include:
- Alport syndrome: A genetic disease in children that leads to kidney, eye, and hearing damage
- Autoimmune kidney disease: Including IgA nephropathy and IgM nephropathy, both of which clog the filtering units of the kidneys with immune proteins
- Chronic kidney disease (CKD): A disease characterized by progressive damage and loss of function in the kidneys
- Connective tissue diseases: Including autoimmune diseases like lupus, rheumatoid arthritis, and Sjögren’s syndrome that directly attack the kidneys
- Diabetic nephropathy: A complication of diabetes in which uncontrolled high blood sugar can damage the blood vessels and filtering units of the kidney
- Kidney cancer: Including the most common form known as renal cell carcinoma
- Polycystic kidney disease: A genetic disorder that causes cysts to form in the kidneys
- Preeclampsia: A potentially dangerous pregnancy complication in which extremely high blood pressure can damage the filtering units of the kidneys
- Renal sarcoidosis: A disease that causes the formation of hardened granules in the kidneys
Causes of overflow proteinuria include:
- Amyloidosis: A rare disease that causes a buildup of a protein called amyloid in different organs, including the kidneys
- Multiple myeloma: A blood cancer that can cause elevated protein levels in the blood as well as damage to the filtering units of the kidneys
Other Causes
Other possible explanations for foamy urine that occur outside of kidney diseases include:
- Medications: Including nicotine, lithium, penicillin, angiotensin converting enzyme (ACE) inhibitors, certain antibiotics, opiates, and chemotherapy drugs
- Retrograde ejaculation: A condition in which the backflow of semen into the bladder can cause pee to foam due to proteins in the seminal fluid
When to See a Healthcare Provider
Foamy pee may mean nothing, particularly if it’s a one-off or short-lasting event. However, you should speak with a healthcare provider if:
- You frequently experience foamy pee, particularly if it is getting worse.
- You find yourself needing to pee more frequently or urgently, especially at night.
- Foamy pee is accompanied by itching, shortness of breath, or swollen hands or feet.
- You have poorly controlled diabetes.
- You are in the latter stages of pregnancy.
- You have a family history of kidney disease.
Diagnosis and Tests for Foamy Urine
The diagnosis of foamy pee typically starts with a urine dipstick test, which detects a type of protein called albumin.
If proteinuria is detected, additional tests will be ordered to narrow the causes, including:
- Urinalysis: A urine dipstick can also detect blood sugar (suggestive of diabetes) or blood (suggestive of kidney injury). A microscopic exam may also detect sperm (suggestive of retrograde ejaculation).
- 24-hour urine collection: This offers a more quantitative analysis of a urine sample
- Albumin test: This blood test measures the level of albumin in the bloodstream.
- Creatinine test: These blood and urine tests measure a common waste product, called creatinine, that serves as a marker for how well the kidneys are functioning.
- Estimated glomerular filtration rate (eGRF): This calculation, based on creatinine test results, measures how effectively your kidneys filter water and waste.
- Albumin-to-creatinine ratio (ACR): This is another calculation based on albumin and creatinine test results that measure the rate of protein excretion over 24 hours.
- Renal ultrasound: This noninvasive imaging test can detect kidney injury, changes in blood vessels or filtering units, and abnormal cysts or growths.
How Do They Treat Causes of Foamy Urine?
The treatment of foamy pee varies by the cause. In some cases, all that may be needed is extra fluid to compensate for dehydration. For conditions like retrograde ejaculation, no treatment may be needed.
However, if proteinuria is diagnosed, treatment may be prescribed to preserve kidney function. Key to this is the management of conditions that contribute to kidney disease, namely hypertension (high blood pressure) that can exert damaging stress on the kidneys, and hyperglycemia (high blood sugar) associated with poorly controlled diabetes.
Treatment options for hypertension include oral medications like:
Treatment options for glycemic control of diabetes include medications like:
Can Changes in Diet Help?
Proteinuria associated with kidney disease may also require the restriction of dietary sodium (salt) below the 2,300 mg recommended daily for healthy adults. For people with chronic kidney disease and/or high blood pressure, the daily sodium intake may be reduced to less than 1,500 mg per day.
How Can You Keep Your Kidneys Healthy?
As an early indicator of CKD, proteinuria can be prevented by keeping your kidneys as healthy as possible. This includes taking steps to minimize risk factors that contribute to CKD.
The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) recommends:
Key Takeaways
- Foamy pee may be due to harmless causes like dehydration, stress, a rapid urine stream, or even cleaning products in your toilet.
- More concerning is the risk of proteinuria associated with kidney-related issues like diabetes, chronic kidney disease, autoimmune diseases, connective tissue diseases, preeclampsia, and even certain cancers.
- A urine dipstick test can detect proteinuria, while other tests and imaging studies can help diagnose or exclude kidney disease as the cause.