Renal colic is pain that occurs due to a stone in the urinary tract. The urinary tract includes the kidneys, ureters, urinary bladder, and urethra.
Stones can develop anywhere in the urinary tract, and they can vary significantly in size. Most stones occur due to a buildup of minerals or other substances, such as uric acid, which stick together in the urine and create a hard mass.
There are several treatment options for urinary stones. However, as many stones pass without surgery, the management of renal colic is often the primary concern during treatment.
In this article, we explain how to recognize renal colic, what causes it, and ways to treat it.
The symptoms of renal colic vary depending on the size of the stone and its location in the urinary tract. Some small stones cause mild renal colic, and a person can pass them in the urine without much discomfort.
Larger stones can cause severe pain, especially if they become stuck and block any small passages in the urinary tract. Susceptible areas include the ureters, which are the tubes through which the urine passes between the kidney and the bladder.
The most common presentation of renal colic is pain on the affected side of the body between the lower ribs and hip. This pain tends to radiate to the lower abdomen and groin.
The pain typically comes in waves that each last 20–60 minutes before subsiding.
Renal colic is just one of the symptoms that urinary stones can cause. Other symptoms that commonly occur alongside renal colic include:
- pain or difficulty urinating
- blood in the urine, which may make it appear pink, red, or brown
- urine that smells unusual
- small particles in the urine
- feeling a constant urgent need to urinate
- cloudy urine
- urinating more or less frequently than usual
Symptoms of a related urinary tract infection (UTI) may occur for some people. These include fever, chills, and a cold sweat. Anybody experiencing any of these symptoms should talk to a doctor.
Anyone experiencing the following symptoms alongside renal colic should contact the emergency medical services or go to the emergency room immediately:
- a complete inability to urinate
- uncontrollable vomiting
- a fever higher than 101°F
Renal colic occurs due to a stone becoming lodged in the urinary tract, which commonly occurs in the ureter. Here, the stone stretches the surrounding area of tissue while trying to pass through, which can be painful.
In addition, restricted urine flow may cause inflammation and increased pressure. The ureter may also spasm, causing pain.
Several different chemicals and minerals can make up a kidney stone. Stones develop due to a few different risk factors, including:
- extra calcium in the urine
- diseases of the gastrointestinal (GI) tract, such as Crohn’s disease or ulcerative colitis
- gout, which occurs due to an excess of uric acid
- certain medications
- cystinuria, in which stones develop from an amino acid called cysteine
- surgeries of the GI tract, such as a gastric bypass
- a family history of urolithiasis
Doctors will often use blood tests to check for increased levels of stone-forming substances in a person’s body. An imaging test can help locate any significant stones in the urinary tract, such as a plain film X-ray, CT scan, or ultrasound.
Medical treatment will often depend on the type of stone. There are several different types of stone, including:
- Calcium stones: These are the most common types of stone and consist of calcium oxalate.
- Uric acid stones: These stones develop when uric acid concentrates in the urine.
- Cystine stones: Cystine stones are rare and occur due to cystinuria.
- Struvite stones: Bacteria in the urinary tract can cause struvite stones, although these are also less common.
People can pass most small stones in the urine. Doctors will recommend hydration, and they may prescribe pain relieving medications to help a person deal with the pain. They will monitor the person until the stone passes.
A range of procedures can help a person remove larger stones and relieve renal colic. These include:
- Ureteroscopy guided stone extraction: This invasive surgical procedure involves a doctor inserting a thin scope with a light and attached camera into the urinary tract. Using this allows them to locate and remove the stone.
- Extracorporeal shock wave lithotripsy (ESWL): ESWL is a noninvasive treatment. It is the process of aiming small sound waves at the kidneys to break up stones into tiny pieces. A person can then pass these fragments in the urine.
- Percutaneous nephrolithotomy: Doctors typically perform this procedure under general anesthesia. They will make a small incision in the person’s back to access the kidney and will remove the stone using a lighted scope and small surgical instruments.
- Stent placement: Sometimes, doctors place a thin tube into a person’s ureter to help relieve the obstruction and promote the passing of stones.
- Open surgery: Some people who cannot pass the stones may require open surgery. However, this has a longer recovery time than other procedures. Doctors will often try to extract or break up the stones so that a person can pass them before considering open surgery.
Treatment may also include medications that help relieve symptoms or reduce the buildup of stones. These treatments may include:
- alkalinizing agents
- calcium channel blockers
- selective alpha-1 blockers
Pain management is an essential step in treatment, as it can improve a person’s quality of life until the stone passes. Doctors may also recommend medications to calm the GI tract and manage any nausea and vomiting.
Placing a heat pack on the side or lower back may calm the muscle spasms that can occur in people with renal colic.
Avoiding renal colic starts with preventing the stones that cause the symptoms.
A doctor may prescribe a thiazide diuretic if a person has a tendency to develop calcium oxalate urinary tract stones.
In other cases, they may recommend that people increase their fluid intake and reduce the sodium in their diet.
Drinking more fluid may not always improve renal colic or help flush stones out of the urinary tract, but it will, at least, prevent dehydration.
Many people benefit from eating a healthful diet that is rich in a variety of whole grains, vegetables, fruits, and lean proteins. Doctors may also advise people to increase their intake of citrus fruits, such as oranges, lemons, and grapefruits.
Many stones will pass on their own, but they may still cause renal colic. Doctors will often explore the best combination of medical and surgical treatment options to help break down larger stones and allow them to pass.
Stones in the urinary tract can sometimes grow again after successful treatment. Taking preventive measures can help people prevent further stones from developing and reduce the symptoms of renal colic.