Foamy Urine: Causes and What to Do

Do you have foamy urine? Here are 7 possible reasons. Don't ignore it!
Foamy Urine: Causes and What to Do
Diego Pereira

Reviewed and approved by el médico Diego Pereira.

Last update: 19 January, 2023

The presence of a certain amount of foam in the urine is considered normal. The food we eat, the amount of water we drink, and other factors all have an influence and can cause foamy urine when expelled. Occasional episodes with a greater than normal presence of bubbles in the urine shouldn’t cause much concern, but if it occurs every day it should be a cause for concern.

Certainly, if you have very foamy urine, it’s always a sign that something isn’t right. If, after urinating, there’s a layer that covers the entire surface in the toilet and you can’t see the bottom of the toilet, then you should look into it. Its causes aren’t always serious, and so today we’ve compiled 7 explanations for foamy urine and what you should do about it.

7 causes of foamy urine

As you can probably already imagine, there isn’t just one reason why your urine becomes foamier. We can reiterate that the presence of foam is considered normal except when it occurs frequently. Let’s take a look at some of the causes.

1. Speed of urination

The main cause of foam in the urine is the speed of urination. When the force of urine output is too strong, then bubbles will usually form. This is completely natural, and is something that happens with other types of liquids as well. Height also plays a role, so the urine will appear foamier in men who urinate standing up.

Bear in mind that water often looks foamy when you turn the tap on full. There’s nothing to worry about, especially when it only happens occasionally. Indeed, the speed of urination varies greatly, so the amount of foam in the urine will vary a lot, and sometimes there won’t be any at all.

2. You haven’t drunk enough water

Foamy urine can be caused by dehydration.
The characteristics of the urine depend on how hydrated we are.

Urine can also appear foamy when it’s highly concentrated. In general, the urine will be more concentrated if you haven’t drunk enough water in the last few hours, and even more so when you have done some type of intense physical activity or have been exposed to the sun. Foamy urine can also be a sign of dehydration. In this case, it will be accompanied by fatigue, weakness, irritability, constipation, and headaches.

3. Too much protein in the urine

The third most likely explanation is that you have excess protein in your urine. Due to chemical factors, when some proteins are expelled in the urine, they can trap pockets of gas on the surface of a liquid, which causes bubbles to be created.

The expulsion of these macromolecules through the urine is called proteinuria, and there are many internal processes that can create it. Stress, fever, heat, intense physical activity, inflammatory processes, aspirin intake, and kidney problems are its main triggers.

4. Certain medications

Another of the main causes of foamy urine is found in the intake of medications. In principle, these are drugs used to treat urinary tract infections.

Phenazopyridine is perhaps the drug that causes this side effect most regularly, so if you’re taking this or other medication to treat an infection, this is likely to be the reason for the foamy urine. This problem will disappear as soon as the treatment is over.

5. Chemicals in toilet water

One cause that must be ruled out is the presence of certain chemicals in the toilet water. Although it may be an unusual cause, in reality many episodes are explained in this way.

Soapy products have foam-promoting properties, so if you use them regularly or permanently they can make your urine look foamy on contact with water.

6. Kidney disease

Foamy urine could be due to kidney damage.
The kidneys are susceptible to damage from a wide variety of diseases.

As experts point out, persistent foam in the urine has traditionally been considered a symptom of kidney disease. Proteins or polypeptides, free amino acids, and other compounds have amphiphilic properties that can function as a surfactant to form urine foam.

The kidneys are responsible for keeping most of them in the body during the filtration process, so that if they fail, their concentration increases in the urine that’s expelled.

For this to be the cause, the foam in the urine must be permanent and the amount of foam must be very noticeable. The person will also notice other symptoms, such as fluid retention, fatigue, weakness, disorientation, and heart palpitations.

If you manifest these symptoms and have a family history of kidney damage, diabetes or high blood pressure, do not hesitate to consult a professional immediately.

7. Diabetes

Foamy urine can be a sign of diabetes. This condition causes high blood sugar levels that chronically produce micro and macrovascular damage. Chronic kidney disease from poorly controlled diabetes is very common (diabetic nephropathy), in which the kidneys lose the ability to filter many substances from the blood.

This is the case with albumin, one of the most abundant proteins in plasmatic serum (the part of the blood that doesn’t have cells). This leads to a phenomenon called albuminuria, which can easily be included within the proteinuria phenomenon mentioned in previous sections.

What to do when detecting foamy urine?

There are several reasons for foamy urine. Fortunately, most of them are benign, so severe cases are relatively rare. The first thing we recommend you do is to assess whether the bubbles that form are a consequence of using detergents or soapy products in the toilet. The answer can be found there, so it’s the first cause that you should rule out.

The second thing we advise you to do is to drink plenty of water. Most people think that they drink more water than they actually ingest, so you can objectively assess the number of liters you drink per day. Measure it with the help of a container, so you make sure that you drink at least 2 liters throughout the day. Remember that your intake should be slightly higher on hot days and when you’re physically active.

If, after a couple of days, you notice that the amount of foam in your urine hasn’t decreased, seek medical attention immediately. The specialists will carry out tests and evaluations to find its possible cause. Don’t postpone the visit for too long, especially if you have the complementary symptoms we have mentioned for each case.

  • Ioannou, K. Diabetic nephropathy: is it always there? Assumptions, weaknesses and pitfalls in the diagnosis. 2017; 16(4): 351-361.
  • Khitan ZJ, Glassock RJ. Foamy Urine: Is This a Sign of Kidney Disease?. Clin J Am Soc Nephrol. 2019;14(11):1664-1666.

Los contenidos de esta publicación se redactan solo con fines informativos. En ningún momento pueden servir para facilitar o sustituir diagnósticos, tratamientos o recomentaciones provenientes de un profesional. Consulta con tu especialista de confianza ante cualquier duda y busca su aprobación antes de iniciar o someterse a cualquier procedimiento.