Foamy Urine and Bubbles in the Urine -Causes and Diagnosis

Most of us do not give the presence of bubbles in the toilet water a second thought when we are urinating. These bubbles occur most of the time as urine strikes the water and small air bubbles form momentarily. It is more likely to occur when disinfectants or soapy residue are already in the water during cleaning of the toilet.

However, there is point where ‘urine bubbles’ are excessive. It can reach the point where urine may for a head of foam on the surface, similar to a foamy beer. At other times the bubbles are not as fine and frothy as foam but nevertheless excessive as compared to previous episodes. This foaminess and bubbles could in fact be a sign of some underlying urinary problem.

What is foamy urine?

Foamy urine refers to a thick head of tiny air bubbles on the surface of urine. It is also referred to as frothy urine. While a slight foam can occur every now and then, persistently foamy urine especially where there is a thick layer of surface foam needs to be investigated for possible medical causes to this excessive bubbling.

A similar phenomenon can occur with larger air bubbles although it usually does not form the same thickness of foam as is seen with tiny bubbles. There are a number of reasons why this may occur and it is not always a problem. The speed of urine that is flowing out of the urethra and even the composition of toilet water can both contribute to foaming.

However, when clear foaming is seem on urine in a collection jar, then it is likely that there is an underlying medical cause. The foam tends to persist for long periods of time as bubbles slowly burst thereby releasing the gas within it. Eventually there is a much thinner layer of bubbles or the urine foam clears up altogether.

Causes of Foamy Urine

There are several possible causes of foamy urine and it is important to consult with a medical professional to isolate the exact cause. The presence of other signs and symptoms may also assist in identifying a possible cause. It is therefore important to report all signs and symptoms to a doctor in order to assist with a faster diagnosis.

Forceful Urination

The force at which urine is passed out is dependent on the strength of bladder muscle contractions, volume of urine in the bladder as well the height at which urine is propelled. Forceful urination causes urine to strike the toilet water at a higher speed. This allows air to enter and form bubbles in the urine-water mixture.


One of the common features of detergents is its ability to form a soapy mixture with water. The greater the agitation, the more bubbles are formed. Therefore bubbles in the urine may at times be due to the presence of these detergents in the toilet water. More bubbles are likely to occur if there is a higher concentration of detergents and if urine is forceful.

Protein in Urine

Proteinuria is the medical term for passing out protein in the urine. This can occur for a number of physiologic and pathologic reasons. Protein in the urine is more likely to lead to the formation of bubbles and specifically foaming of the urine. There are many reasons why protein may be passed out in the urine, including:

  • Strenuous exercise like running a marathon.
  • Extreme environmental heat or cold.
  • Dehydration.
  • Using certain drugs.
  • Pregnancy.
  • Psychological stress.

Although these conditions may not always be considered serious, protein in the urine should not be ignored. It could be a sign of a more serious underlying cause. There are certain diseases where proteinuria may also occur, including:

  • Poisoning especially with heavy metals.
  • Diabetes mellitus.
  • Kidney failure and other kidney diseases.
  • Liver failure and other liver disease.
  • Cardiac failure, high blood pressure (hypertension) and other heart diseases.
  • Fever of any cause.
  • Cancers.
  • Systemic lupus erythematosus (SLE).
  • Sarcoidosis.

Urinary Tract Infections

Although urinary tract infections can also cause proteinuria, it is worth discussing this type of infection on its own. Urinary tract infections (UTIs) are common, especially in females, and most of the time these infections are restricted to the bladder. It occurs when microbes enter through the urethra and move up the urinary tract.

At other times the infection may spread via the blood stream to the kidneys and other urinary organs. These infections cause inflammation in the urinary tract. Pus may also be formed. Inflammation and pus gives rise to protein and this is further compounded if the kidney passes out protein when damaged or if there is bleeding into the urine.

There are usually a host of other symptoms apart from the foamy urine. This may include burning when urinating, frequent urination, offensive smelling urine and a persistent urge to urinate. However, sometimes urinary tract infections can be largely asymptomatic apart from the presence of foamy urine.

What to do about foamy urine?

Foamy or froth urine needs to be assessed by a medical professional. This often involves laboratory tests like a urinarlysis. Urine is collected, sometimes over a 24 hour period, and then sent to a laboratory or further testing. The results may point towards a specific cause and sometimes further diagnostic investigations are necessary to confirm the diagnosis.

Often a medical doctor will first perform a urine dipstick test. By using these strips, it is possible to isolate the cause of the foamy urine. Test strips dipped into urine will indicate whether there is protein in the urine, an infection, white blood cells and other important diagnostic markers that will assist with the diagnosis.

Ensure that urine samples are not tainted as it can lead to a misdiagnosis. Use a clean collection jar provided by a doctor or laboratory. Mid-stream urine is often a better sample as any contaminants are expelled at the start of urine. A doctor or nurse will advise on how to collect the urine sample.

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