What are ureteral stones?
Ureteral stones are kidney stones that have become stuck in one or both ureters (the tubes that carry urine from the kidneys to the bladder).
If the stone is large enough, it can block the flow of urine from the kidney to the bladder. This blockage can cause severe pain. Kidney stones are formed from excess concentrations of minerals and salts in the urine. These minerals form crystals that grow into stones. Most kidney stones are calcium-based.
Many kidney stones are tiny. Some are too small to see with the naked eye, pass through the urine, and do not cause a problem. Larger stones that get stuck in the urinary tract can cause pain that may be severe.
How common are ureteral stones?
Each year in the United States, about 1 in 1,000 adults is hospitalized for urinary tract stones. They are most common among middle-aged adults. Over your lifetime you have a 1 in 8 chance of forming a stone.
Symptoms and Causes
What are symptoms of ureteral stones?
Tiny stones that pass through the urinary system on their own may not cause any symptoms. However, stones that block the ureter or any of the kidney’s drainage tubes may cause symptoms that include:
- Severe, intermittent (comes and goes) pain in the upper flank (in the back, under the lower ribs) that can radiate (spread) to the lower abdomen, and;
- Nausea and vomiting.
Call your doctor right away if you have these symptoms.
Diagnosis and Tests
How are ureteral stones diagnosed?
Kidney or ureteral stones are diagnosed by your doctor. He or she may:
- Give you a physical exam and ask about your medical history.
- Test your urine to see if it contains substances that form stones.
- Test your blood to see if you have health problems that may have led to stones.
- Order an imaging test to find the location of the stones. Imaging tests may also help to see if you have health problems that may have led to stones. Ultrasound is an effective imaging test to look for blockage. A computed tomography (CT) scan will help guide therapy by informing the doctor of the size, location, and hardness of the stone.
Management and Treatment
How are ureteral stones treated?
Treatment of ureteral stones depends on the size and location of the stones and the substances from which they are formed. Treatment may also be directed by your current circumstances, such as obesity, the use of anticoagulants (blood thinners), and other considerations. The size and location of the stone will give you an idea of the likelihood that you can pass it.
If you have larger stones and your urinary tract is blocked, a urologist (a doctor who specializes in the urinary tract) may treat you with the following:
- Shock wave lithotripsy: During this procedure, you are set up with a machine that produces focused shock waves to break up the stones. The small pieces of the stones then pass through your urinary tract when you urinate. This is the least invasive option.
- Ureteroscopy: The urologist feeds a long tube with an eyepiece, called an ureteroscope, into your urethra (the hole where urine leaves your body). The doctor feeds the scope through the bladder into the ureter, finds the stones, and removes or breaks them up with lasers.
- Percutaneous nephrolithotomy: This procedure, which is used for larger or irregularly shaped stones, uses a scope to find and remove the stones. The scope is inserted directly into your kidney through a small incision (cut) in your back.
How can ureteral stones be prevented?
You will not have ureteral stones if you do not have kidney stones. If you have had a kidney stone, your doctor can help you learn how it was formed and what you can do to prevent others from forming. Your doctor may treat the stone BEFORE it moves into the ureter and causes pain.
You may be asked to change your diet in the following ways:
- Drink more fluids. (Increase to 2 to 3 liters a day; preferably water, but lemonade, orange juice, and other drinks are options.)
- Limit animal protein (found in meat, eggs, fish).
- Control sodium intake (less than 1500 mg/day).
- Limit oxalate (found in spinach, nuts, wheat bran).
You may also be prescribed medications to help prevent the formation of kidney/ureteral stones.