CLOUDY URINE: POSSIBLE CAUSES AND TREATMENTS - MEDICINE - 2025

The urine turbid and fetid can sometimes be a sign of severe disease of the urinary tract. This sign is underestimated by most patients when in reality it should be an alarm signal, since it indicates that something is not right in our body.

Urine is the result of a complex filtration process that takes place in the kidneys; It is mainly composed of water and some solutes (excretion products), which are present in such a quantity that they do not modify the transparency of the water that is part of the urine.

When for some reason the amount of solutes increases or there is the presence of materials that would not normally be in the urine, it is no longer transparent and takes on a cloudy appearance, as if there were some type of dissolved material visible in it.

In the biochemical field, this is due to an increase in the concentration of certain solutes such as proteins, the presence of materials that are not normally in the urine (such as urate crystals) or an increase in the number of cells (which it is usually very low).

The simple urine test usually gives a very clear idea of ​​what is happening microscopically and chemically in the urine, so that the doctor can guide the diagnosis quite accurately from the results of this test.

Possible causes

Urine can become cloudy due to multiple conditions, which would occupy an entire volume of a urology book. Hence, in this post we will focus on the most frequent causes, among which are:

- Urinary infection.

- Hematura (blood in the urine).

- Proteinuria (increased amount of protein in the urine).

- Diabetes.

- Kidney stones.

Of all the causes that can make urine cloudy, infections are by far the most common; However, other conditions should not be underestimated since, when they are present and not diagnosed in time, there may be irreversible damage to the urinary tract.

Urinary infection

UTIs are the most common cause of cloudy urine. In these cases, the presence of large numbers of bacteria, dead urothelium cells, cells of the immune system (white blood cells), as well as chemical substances such as antibodies, make the urine no longer transparent.

In the most severe cases where pus is detected in the urine (pyuria) the urine is no longer cloudy, but completely loses transparency.

All urinary infections - both low (cystitis) and high (pyelonephritis) - present with changes in the transparency of the urine, which also becomes fetid.

Although most people associate dysuria (burning during urination) with urinary tract infections, this symptom is sometimes absent and the only indication of a urinary tract infection is cloudy urine, particularly in very young babies and older adults, especially those with some degree of cognitive deficit.

Hematuria

Hematuria is the presence of red blood cells in the blood. In cases of gross hematuria (where the amount of blood is considerable) the urine turns red; however, these are not the majority of cases, microhematuria being more frequent.

Microhematuria is the presence of red blood cells in the urine (these cells are not normally present in the urine or in extremely low amounts), which makes the urine cloudy.

The more red blood cells the more cloudy the urine. However, in these cases it is essential to identify the cause in order to start treatment, since the causes of microhematuria range from urinary infections to kidney cancer, to kidney stones and inflammatory kidney disease (nephritis).

Proteinuria

Proteinuria is the increase in the amount of protein in the urine, mainly albumin. Although the presence of a certain amount of protein in the urine is normal, it should not exceed the levels considered normal.

When this occurs it is due to damage to the kidney pores, which allow more than normal protein to escape from the bloodstream into the urine.

This is due to multiple causes, ranging from nephrotic syndrome to hypertensive nephropathy, through a myriad of kidney diseases that present with proteinuria.

Diabetes

Diabetes is one of the most common causes of proteinuria due to the development of diabetic nephropathy.

In addition, in cases of decompensated or poorly controlled diabetes, excess sugar in the blood begins to be expelled through the urine, a phenomenon known as glycosuria.

Since the normal levels of glucose in the urine are very low (sometimes undetectable), the presence of glucose molecules in the urine often makes the urine cloudy.

As with hematuria and proteinuria, the higher the solute concentration (in this case, glucose), the more cloudy the urine will be.

Kidney stones

Kidney stones are due to an increased presence of urate crystals in the urine. The more crystals there are, the more stones will form, but also the concentration of crystals in the urine will increase.

These crystals work just like any other solute (red blood cells, pus, proteins, etc.), so that the higher the concentration, the more cloudy the urine will be.

If we add to this the fact that kidney stones are usually associated with a higher frequency of urinary infections, the conditions are given so that the urine of patients with this condition is cloudy.

Treatment

A good strategy in either case is to increase water consumption since this way the solutes are diluted and the urine tends to be more crystalline.

However, this strategy is useful only to prevent the damage of the urinary tract from spreading and in no case does it solve the problem; it can even aggravate it as in nephrotic syndrome cases; therefore, it is mandatory to consult a specialist whenever the urine becomes cloudy.

After a thorough clinical examination and some tests it will be possible to establish the diagnosis with certainty, and from there to decide which is the best treatment.

As is often the case with nonspecific symptoms that may be present in different diseases, the specific treatment will depend on the cause of the problem.

In cases of infections, the administration of appropriate antibiotics will suffice. On the other hand, when there are kidney stones (stones or stones), some type of invasive intervention may be necessary to remove the stones, as well as the administration of medications that limit the formation of crystals in the urine.

Kidney disease

In cases of kidney diseases such as nephritis, diabetic nephropathy or hypertensive nephropathy, it will be necessary not only to treat the kidney condition but also to control the underlying disease that produced it.

References

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