What Is Renal Colic? Kidney Stone Symptoms

Renal colic is caused as the stone is passing through your ureter, resulting in pain due to:

• Muscle contractions: The muscles around the stone contract in an effort to pass the stone, resulting in severe pain.
• Injury: Sometimes, as the stone passes through the ureter, its jagged edges cut and injure the inner lining. This may also cause renal pain.
• Acute obstruction: In some cases, the stone is large enough to cause total obstruction of the urinary tract and disruption of the urinary flow (urinary stasis), which in turn distends the ureter (hydroureter) and results in reflexive smooth muscle spasm due to nerve stimulation.

Factors that can increase your risk of developing urinary stones include:

• Family history of kidney stones
• Dehydration from not drinking enough water
• Eating food with too much salt or sugar
• Obesity
• Hyperuricemia
• Recurrent urinary tract infections

Symptoms mainly depend on the size of the stone and where it has affected the urinary tract. Small-sized stones cause mild renal colic and can be passed relatively easily in urine. Larger stones can cause pain, particularly if they block one of the ureters.

Common symptoms of renal colic include:

• Excruciating pain between your ribs and hip or in your lower abdomen
• Pain that spreads to your back or groin
• Vomiting
• Nausea

Other symptoms of urinary stones include:

• Pain when you urinate
• Urgent need to urinate
• Blood in the urine, which may be pink, red, or brown
• Foul-smelling urine
• Small bits of stones in your urine

Types of renal stones include:

1. Calcium stones: Most common types of stones and made up of calcium oxalate. Recurrent urinary tract infections, inadequate fluid intake, and tendency to hold in urine can result in calcium stones.
2. Uric acid stones: Occur when uric acid crystallizes in the urine. Uric acid is often the product of purine metabolism. When you eat foods high in purines, such as meat products, dairy, shellfish, and alcohol, excess uric acid forms in the body. The tendency to develop uric acid stones often runs in families.
3. Cystine stones: Rare and occur due to cystinuria.
4. Struvite stones: Caused by an upper urinary tract infection or infection in the kidneys. They can grow quite large and cause pain and infections if left untreated.

The direction in which renal pain radiates often provides your doctor with clues regarding the presence of urinary stones. 

Your doctor will perform a urine examination and blood tests to assess serum uric acid levels, serum electrolyte levels, and urea and creatinine levels, checking for renal functions and possible hyperuricemia. 

An imaging test (ultrasound or a computed tomography scan) can help detect stones in the urinary tract.

With adequate hydration, you should be able to pass small-sized stones without an issue. Your doctor may administer intramuscular painkillers such as diclofenac or antispasmodic medications, or diuretics if required.

If you have a larger stone, your doctor may perform a procedure to remove the stone:

• Extracorporeal shock wave lithotripsy: Shock waves are focused on your kidneys to break up the stones into tiny pieces. You can then pass the pieces in your urine.
• Ureteroscopy: A light scope is inserted through your urethra and bladder to remove the stone.
• Percutaneous nephrolithotomy: Instruments are inserted through a small cut in your back to remove the stone.

Your doctor may prescribe temporary medications to reduce renal colic pain, such as:

• Nonsteroidal anti-inflammatory drugs such as Motrin IB and Advil (ibuprofen)
• Drugs to prevent muscle spasms
• Opioids for acute pain