Urine crystals form when there are too many minerals in a person’s urine. They often occur in the kidneys.
When there is an excessive buildup of one or more minerals, a urine crystal can form into a stone.
Typically, urine crystals will cause limited signs and symptoms unless large enough stones develop. When this occurs, the stone may pass naturally out of the body, or some medical intervention may be necessary to help remove the stone.
Here, we look at some of the most common types of urine crystals, including their causes, symptoms, and potential treatment options.
Small urine crystals may not always cause symptoms. However, a person with larger urinary stones, or stones that are moving through the urinary tract, may experience a range of uncomfortable symptoms, including:
Urine crystals form when an excessive number of minerals are present in the urine. Different types of urine crystals form for different reasons.
Sometimes, eating a diet too high in protein or salt can cause urine crystals to form. Dehydration from not drinking enough fluids can also lead to the formation of urine crystals.
In some cases, an underlying health condition may cause urine crystals, and the person will need treatment for the condition.
There are several different types of urine crystals. The type of urine crystal depends on the difference in the chemicals that make up the crystal, as well as the underlying cause of the buildup.
The following are some of the most common types of urine crystals that may appear in a urine test:
Struvite is a type of urine crystal that consists of phosphate, ammonium, magnesium, and calcium.
Struvite typically forms as a result of a urinary tract infection (UTI) or when a person has difficulty emptying their bladder.
Uric acid stones
According to a study on uric acid stones, the primary cause of these stones is highly acidic urine. The authors also note that less common causes can include:
- a high level of uric acid
- low urine volume
- metabolic syndrome, which is several conditions that occur together and increase a person’s risk of heart disease, diabetes, and stroke
- gout, which is pain and inflammation due to an excess of uric acid
- excess protein
Treatment for uric acid stones typically includes dietary changes and an increase in daily liquid intake.
According to the National Kidney Foundation, calcium oxalate stones are the most common type of kidney stone. Having too much oxalate in the urine can cause these stones to form.
Oxalate is a common chemical that is present in a range of foods. As a person digests foods, the kidneys remove oxalate through the urine.
If a person is not well-hydrated, chemicals can stick together and create a stone that may eventually pass or become stuck in the kidney.
Some people are more at risk than others of developing calcium oxalate stones. Risk factors include:
- digestive diseases, such as irritable bowel syndrome (IBS) or Crohn’s disease
- a diet high in protein, sodium, sugar, or oxalate
- other medical conditions, such as Dent’s disease
Cystine stones are another type of stone that forms in the kidneys or urinary tract. According to the National Kidney Foundation, cystine stones are typically larger than other kidney stones and tend to recur.
Cystinuria causes cystine stones. Cystinuria is a condition in which a substance called cystine gets into a person’s urine. When too much is present, a stone may form.
Cystinuria is a genetic disorder, and it is not common.
If urine crystals form into stones, a person is at risk of developing complications. According to the National Kidney Foundation, some complications of larger, untreated stones include:
If the crystals do not form into stones, or if the stones are small enough, they will pass out of a person’s body in their urine. Smaller stones may or may not cause symptoms and are unlikely to cause complications.
Not all urine crystals warrant a trip to the doctor. However, a person should see their doctor if they are having any urinary symptoms, such as pain, frequent urination, or fever.
A person should also see their doctor about urine crystals if they get them frequently. It is possible that dietary changes may help. In some cases, treatment for an underlying health condition may be necessary to help prevent future stones from forming.
According to the National Institute of Diabetes and Digestive and Kidney Diseases, a doctor will usually order a 24 hour urine sample following the passing or treatment of a urine stone.
During this test, the person will collect samples of their urine over 24 hours, which will go to a lab for analysis. The results can help the doctor determine whether the person is producing enough urine in a day and if they have too many minerals in their urine.
A doctor will likely also ask about the person’s symptoms. They may order additional tests to check for other underlying health issues.
Treatment will depend on the type of stone that a person has developed or is prone to developing. In some cases, a doctor may recommend over-the-counter pain relievers and advise the person to increase their fluid intake to help flush the stone out.
If the stone has grown too large, a doctor may have to help break it up. They can use several different methods to break up a larger stone, including:
- shock wave lithotripsy, which breaks the stone into small pieces
- cystoscopy and ureteroscopy, which allow the doctor to find and break up or remove a larger stone
- percutaneous nephrolithotomy, which also allows the doctor to view and remove a larger stone
Drinking enough water throughout the day and staying well-hydrated helps prevent crystals from forming in the urine.
If a person consumes too much of a certain mineral, a doctor will likely recommend a diet that minimizes or eliminates that particular mineral.
Finally, a doctor may prescribe medications or supplements to help prevent the formation of stones. Some medications and supplements that a doctor may prescribe include:
- potassium citrate
- allopurinol, for uric acid
- mercaptopropionyl glycine, which doctors often use to treat heart issues
Urine crystals are not necessarily a cause for concern. In many cases, they can pass on their own with minimal intervention.
Many have benign and preventable conditions, such as dehydration or the excessive consumption of a certain food.
If people require treatment, a doctor may advise extra fluid intake and medications to dull pain. In some cases, if the stone is large and in a potentially harmful location, a doctor may remove the stone.