What Do Cholesterol Crystals In Urine Indicate?

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Crystals in urine 

Your urine can be a good indicator of what is occurring inside your body and your general health and well-being. 

Crystal formation in the urine is called crystalluria.¹ 

Crystals in urine are formed from minerals and compounds. These minerals and compounds may remain free and separated from one another in urine, or they may clump together and form solid masses of numerous shapes and sizes. Minerals and compounds may bond together in the urine while still in the urinary tract or after urine has been passed.

Most crystals form when urine is too highly concentrated. This is when there is an excessive number of minerals and compounds and not enough liquid — which is the perfect environment for crystals to form. If left untreated, crystals can become large and develop into kidney stones, obstructing the renal tract and possibly leading to acute renal failure.

The pH of your urine is also known to contribute to the formation of crystals.

Normal urine contains many compounds and minerals from which crystals can form — therefore, most crystals are not problematic and may be present in the urine of healthy individuals. However, some crystals can be an indication of a serious medical condition.

Main causes of cholesterol crystals and other crystals in the urine:

  • Dehydration is the leading cause of urine becoming too concentrated

  • Eating an excess of particular macronutrients and micronutrients, the most common being protein and vitamin C

  • Consuming high amounts of salt, sugar, saturated fats, trans fat, and alcohol

  • Smoking

  • Taking illicit drugs

  • High cholesterol

  • Excess body weight

  • Certain medications and supplements

  • A urinary tract infection

Cholesterol crystals in the urine


Small amounts of cholesterol crystals can be present in normal urine, which are thought to be from the normal breakdown of cells. However, elevated levels of cholesterol crystals are abnormal. If excessive levels are found in urine, they may be a strong indicator of nephrotic syndrome or kidney failure. The reason for this is not well understood. 

Cholesterol crystal growth may be highly promoted by acidic and concentrated urine.

Symptoms of nephrotic syndrome include puffiness in the legs, ankles, feet, face, and hands, weight gain, fatigue, foamy urine, and reduced appetite.

The main symptoms of kidney failure include decreased urine output, headaches, puffiness in the legs and ankles, fatigue, insomnia, chest pain, nausea, and confusion. 

Appearance: Cholesterol crystals are unique in their shape and are generally easy to identify in urine samples. They are see-through with well-defined outlines. They usually take on a rectangular shape with a notch in one or more corners.

Other types of crystals in the urine

Around 100 crystalline formations have been discovered. Only 15 are well-researched and often seen in urine samples. The others are rare, and little is known about them or their causes.

Common types of crystals in the urine

Uric acid

Uric acid crystals are generally the most common type of crystals found in urine among healthy people. A likely cause is the consumption of protein-rich foods and meat.

High levels in your urine may indicate that your body is not digesting proteins or, in some rare cases, acute uric acid nephropathy.

Appearance: Uric acid crystals have a distinct amber color and can occur in a variety of forms, from a simple square shape to a diamond or cylinder shape.

Calcium oxalate 

These crystals are commonly found in healthy people, likely as a result of eating oxalate-rich foods such as chocolate, beetroot, rhubarb, and spinach.

An extremely high level of calcium oxalate crystals in the urine may be highly suggestive of hyperoxaluria — a serious renal stone disease.

Appearance: They are colorless, and their forms are pyramid and envelope shaped. 

Abnormal types of crystals in the urine


Cystine crystals are not usually found in healthy individuals. These crystals may indicate cystinuria — a hereditary disease that causes cystine to form into stones in the kidneys, bladder, and ureters.

Symptoms of cystinuria include blood in the urine, pain in the side of the back, groin, pelvis, or abdomen, and nausea and vomiting.

Appearance: They are easily identified via a microscope and usually appear as a six-sided hexagon-like shape. 

Struvite (triple phosphate)

These crystals are only found in the case of a urinary tract infection (UTI).

The main symptoms of a UTI are a burning sensation when urinating, a strong and persistent urge to urinate, cloudy urine, fever and chills, nausea, and vomiting. 

Struvite takes on many shapes, such as a rod, coffin, pyramid, elongated hexagon, and large x-shape. 


These crystals can indicate leucinosis — a rare inherited disorder — also called the “maple syrup urine disease”. They can also suggest Hartnup disease, which is the inability to absorb certain protein building blocks, specifically leucine.

Symptoms of leucinosis include lethargy, vomiting, and a maple syrup smell in urine and sweat. 

Symptoms of Hartnup disease include skin rashes, anxiety, intense and sudden mood swings, unsteady walking, tremors, hallucinations, and delusion. 

Appearance: These crystals appear as oily-looking circles with lines in the middle. 

Diagnosis and treatment of crystals

A urinalysis is often the initial examination to determine whether you have crystals in your urine.

A urinalysis is likely to occur in the following steps: 

  1. You will be asked to provide a urine sample.

  2. The urines’ physical properties, such as coloring and opacity, will be examined.

  3. A dipstick is used to test for components within the urine and to determine the acidity or alkalinity of the urine.

  4. If cholesterol crystals are suspected, refrigeration of your urine sample is important, as cholesterol crystals do not appear unless refrigerated.

  5. A lab technician will then examine a small drop of your urine sample under a microscope to examine if any crystals are present.

Depending on the findings from your urinalysis, your doctor may order more tests or offer treatment advice. Treatment varies depending on the crystals found in the urine and your individual situation.

Urine crystals and cholesterol 

Two studies found that individuals with high cholesterol levels were likely to have high levels of calcium oxalate and uric acid crystals and stones in their urine. In addition, those with high cholesterol were more likely to form larger crystals and, in many cases, stones in their urine compared with those that did not have high cholesterol. 

Research shows that taking cholesterol-lowering medications, particularly statins, may effectively reduce the occurrence and formation of crystals and stones in urine if you have high cholesterol.

Seek medical advice from your doctor before taking any cholesterol-lowering medications. 

Reducing your risk of crystals 

Lifestyle and dietary changes can effectively reduce crystal formation, but it depends on the crystals formed. Those that are common would benefit most from lifestyle and dietary changes. 

Research² suggests that prevention of cholesterol crystal formation may be possible with medications or drug interventions. These can help reduce vessel wall inflammation and lower plaque cholesterol load. 

You could try the following dietary and lifestyle changes:

  • Drinking plenty of fluids, mostly water, is one of the most effective ways to dilute your urine and prevent crystal formation.

  • Reducing your intake of salt, processed sugars, and saturated and trans fats can help — particularly if you are consuming an excess, as high levels may promote crystal and stone growth.

  • Decreasing your protein intake may help if you are consuming large amounts, as protein can cause urine to become highly acidic.

  • You could try reducing your smoking and intake of alcohol, as excessive amounts can dehydrate your body.

Before making any dietary and lifestyle changes, or if you are unsure about what changes to make, you should speak with your doctor or healthcare provider first. They will be able to provide safe and appropriate professional advice to you and your individual situation. 

When you should see a doctor

Seek medical attention from your doctor or healthcare provider if you notice a change in your urine color, smell, or quantity, if you have pain or a burning sensation when urinating, or if you have difficulty passing urine.

The lowdown

Detecting cholesterol crystals in your urine may not indicate anything more than normal cell breakdown. However, in rare cases, it could be the result of a serious health condition. This is likely to depend on how many crystals are detected in your urine, your urine pH, physical examination of your urine through urinalysis, and further tests and examinations. 

Depending on the extent of your cholesterol crystal formation(s) and your current health status, medication, surgery, lifestyle, and dietary changes are likely to be the best treatment options.

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