Kidney Stones & Bilateral Groin Pain

Kidney stones (renal lithiasis) are small crystalline stones that can form in the kidneys of both men and women, although more commonly in men. These stones, usually the result of an underlying health condition, must eventually pass from the kidneys and through the urinary tract. The process of passing a stone can cause severe pain, especially in the lower back and bilateral groin area (both sides of the groin); according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), kidney stones are "one of the most painful of the urologic disorders."

Formation

• Kidney stones can be made up of several different chemicals. Other chemicals within urine normally inhibit or dissolve stone-forming substances. However, for a number of reasons, the stone-inhibiting chemicals in urine may not always function properly. When this happens, stone-forming chemicals are allowed to crystallize, becoming kidney stones.

Types

• There are four different types of kidney stone, each made up of different chemicals. The most commonly occurring are calcium stones. These stones are formed when calcium combines with another substance, such as oxalate or phosphate. Cystine stones form as the result of a genetic disorder. Uric acid stones are composed of uric acid crystallizations. And the fourth type, struvite stones, usually forms as the result of a urinary tract infection (UTI). Struvite stones are the one kind that occur more in women than men.

Passing and Pain

• Most of the pain associated with kidney stones occurs as the result of the stone passing from the kidney and travelling through the ureter to the bladder. A passing stone may block the passage of urine from the kidney, causing it to swell. The result is usually intense pain in the lower back and upper bilateral groin area. As the stone continues to pass into the bladder and out through the urethra, the pain may migrate farther down into the groin and, in men, the testes. Kidney stone pain varies and may be described as either an aching, sharp, cramping, stinging, throbbing or numbing pain, or any combination of pain sensations.

Risk Factors

• While cystine stones are the result of a genetic disorder, most other kidney stones are the result of underlying health issues. According to MedlinePlus, the main risk factor for kidney stones is dehydration. Staying fully hydrated aids in proper urinary function and therefore in the inhibition of kidney stone formation. Kidney stones occur more frequently in those who are obese and those who regularly consume foods that are high in protein or sodium. High blood pressure and certain surgeries may also contribute to stone formation.

Complications and Procedures

• While most stones are small enough to pass naturally, a stone that is too big to pass can cause major problems and complications in the kidney/urinary tract. If a stone becomes stuck there are a few possible removal options. The oldest and most outdated method is open surgical removal. Extracorporeal shock wave lithotripsy (ESWL) is the most common method of oversized stone removal; it uses shock waves to break up the kidney stone into smaller, passable pieces. If a stone is especially large, percutaneous nephrolithotomy, a method of inserting a tube through a small incision in the back and removing the stone may be required. For stones lodged in the ureters, a process called ureteroscopic stone removal may be required.