Kidney Stones or Renal Calculi are solid masses made of crystals. Kidney Stones or Renal Calculi usually originate in your kidneys but can develop anywhere along your urinary tract. The urinary tract includes the kidneys, ureters, bladder, and urethra.
The kidney acts as a filter for blood, removing waste products from the body and making urine. It also helps regulate electrolyte levels that are important for body function. Urine drains from the kidney through a narrow tube called the ureter into the bladder. When the bladder fills, and there is an urge to urinate, the bladder empties to the outside through the urethra, a much wider tube than the ureter. In some people, Chemicals crystallize in the urine and form the beginning, or nidus, of a kidney stone. Theses stones are very tiny when they form, smaller than a grain of sand, but gradually can grow over time an inch or larger. Urolithiasis is the term that refers to the presence of stones in the urinary tract, while Nephrolithiasis refers to kidney stones and Ureterolithiasis refers to stones lodged in the ureter. The size of the stone does not matter as much as where it is located and whether it obstructs or prevents urine from draining. When the stone sits in the kidney, it rarely causes problems, but when it falls into the ureter, it acts as a dam. As the kidney continues to function and make urine, pressure builds up behind the stone, but it also helps push the stone along the course of the ureter. When the stone enters the bladder, the obstruction in the ureter is relieved, and the symptoms of a kidney stone are resolved.
Types of Kidney Stones or Renal Calculi
Knowing the type of Kidney Stones or Renal Calculi helps determine the cause and may give clues on how to reduce your risk of getting more Kidney stones or Renal Calculi. Types of Kidney Stones or Renal Calculi include:
Most Kidney Stones or Renal Calculi are calcium stones, usually in the form of Calcium Oxalate. Oxalate is a naturally occurring substance found in food. Some fruits and vegetables, as well as nuts and chocolates, have high oxalate levels. Your liver also produces oxalate. Dietary factors, high doses of vitamin D, intestinal bypass surgery and several metabolic disorders can increase the concentration of calcium or oxalate in urine. Calcium stones may also occur in the form of calcium phosphate.
Struvite stones form in response to an infection, such as a urinary tract infection. These stones can grow quickly and become quite large, sometimes with few symptoms or little warning.
Uric Acid Stones
Uric acid stones can form in people who do not drink enough fluids or who lose too much fluid, those who eat a high-protein diet, and those who have gout. Certain genetic factors also may increase your risk of uric acid stones.
These stones form in people with a hereditary disorder that causes the kidneys to excrete too much of certain amino acids (Cystinuria).
Other, rarer types of Kidney Stones or Renal Calculi also can occur.
Signs and Symptoms of Kidney Stones or Renal Calculi
A Kidney Stone or Renal Calculi may not cause symptoms until it moves around within your kidney or passes into your ureter – the tube connecting the kidney and bladder. At that point, you may experience these signs and symptoms:
- Severe pain in the side and back, below the ribs
- Pain that spreads to the lower abdomen and groin
- Pain that comes in waves and fluctuates in intensity
- Pain on urination
- Pink, red or brown urine
- Cloudy or foul-smelling urine
- Nausea and vomiting
- Persistent need to urinate
- Urinating more often than usual
- Fever and chills if an infection is present
- Urinating small amounts of urine
Pain caused by a kidney stone may change – for instance, shifting to a different location or increasing in intensity -as the stone moves through your urinary tract.
Treatment of Kidney Stones or Renal Calculi:
Treatment for Kidney Stones or Renal Calculi varies, depending on the type of stone and the cause.
Small stones with minimal symptoms
Most kidney stones won’t require invasive treatment. You may be able to pass a small stone by:
- Drinking water: Drinking as much as 2 to 3 quarts (1.9 to 2.8 liters) a day may help flush out your urinary system. Unless your doctor tells you otherwise, drink enough fluid – mostly water – to produce clear or nearly clear urine.
- Pain Relievers: Passing a small stone can cause some discomfort. To relieve mild pain, your doctor may recommend pain relievers such as ibuprofen (Advil, Motrin IB, others), acetaminophen (Tylenol, others) or naproxen sodium (Aleve).
- Medical Therapy: Your doctor may give you a medication to help pass your kidney stone. This type of medication, known as an alpha-blocker, relaxes the muscles in your ureter, helping you pass the kidney stone more quickly and with less pain.
Large stones and those that cause symptoms
Kidney stones that can’t be treated with conservative measures – either because they’re too large to pass on their own or because they cause bleeding, kidney damage or on-going urinary tract infections – may require more extensive treatment. Procedures may include:
Treatment of Kidney Stones or Renal Calculi
It is done using sound waves to break up stones. For certain kidney stones depending on size and location, your doctor may recommend a procedure called Extracorporeal Shock Wave Lithotripsy (ESWL). ESWL uses sound waves to create strong vibrations (shock waves) that break the stones into tiny pieces that can be passed in your urine. The procedure lasts about 45 to 60 minutes and can cause moderate pain, so you may be under sedation or light anesthesia to make you comfortable. ESWL can cause blood in the urine, bruising on the back or abdomen, bleeding around the kidney and other adjacent organs, and discomfort as the stone fragments pass through the urinary tract.
Surgery to remove very large stones in the kidney. A procedure called Percutaneous Nephrolithotomy (PCNL) involves surgically removing a kidney stone using small telescopes and instruments inserted through a small incision in your back. You will receive general anesthesia during the surgery and be in the hospital for one to two days while you recover. Your doctor might recommend this surgery if ESWL was unsuccessful.
Using a scope to Remove Stones
To remove a smaller stone in your ureter or kidney, your doctor may pass a thin, lighted tube (ureteroscope) equipped with a camera through your urethra and bladder to your ureter. Once the stone is located, special tools can snare the stone or break it into pieces that will pass in your urine. Your doctor may then place a small tube (stent) in the ureter to relieve swelling and promote healing. You may need general or local anesthesia during this procedure.
Parathyroid Gland Surgery
Some calcium phosphate stones are caused by overactive parathyroid glands, which are located on the four corners of your thyroid gland, just below your Adam’s apple. When these glands produce a too much parathyroid hormone (hyperparathyroidism), your calcium levels can become too high, and kidney stones may form as a result. Hyperparathyroidism sometimes occurs when a small, benign tumor forms in one of your parathyroid glands or you develop another condition that leads these glands to produce the more parathyroid hormone. Removing the growth from the gland stops the formation of kidney stones. Or your doctor may recommend treatment of the condition that’s causing your parathyroid gland to overproduce the hormone.