Your kidneys filter your blood and remove the extra waste and water as urine. Kidney stones form when some waste materials clump together to form a solid crystal. These can be as small as a grain of sand to as big as a golf ball and can block the flow of urine, cause infections and kidney damage.
Kidney stones are often very painful, and can keep happening in some people. Kidney stone attacks lead to more than 2 million health care provider visits and 600,000 ER visits each year. People tend to get stones in midlife. During midlife, family and work commitments are at their highest, which make kidney stones costly. The diagnosis, treatment and prevention of kidney stones, as well as the lost time from work because of stones, cost almost $5.3 billion each year.
Common symptoms of kidney stones are:
• A sharp, cramping pain in the back and side, often moving to the lower abdomen or groin. Some women say the pain is worse than childbirth labor pains. The pain often starts suddenly and comes in waves. It can come and go as the body tries to get rid of the stone.
• A feeling of intense need to urinate.
• Urinating more often or a burning feeling during urination.
• Urine that is dark or red due to blood. Sometimes urine has only small amounts of red blood cells that can’t be seen with the naked eye.
• Nausea and vomiting.
• Men may feel pain at the tip of their penis.
What causes kidney stones?
Low urine volume
A major risk factor for kidney stones is constant low urine volume. Low urine volume may come from dehydration (loss of body fluids) from hard exercise, working or living in a hot place, or not drinking enough fluids. When urine volume is low, urine is concentrated and dark in color. Concentrated urine means there is less fluid to keep salts dissolved. Increasing fluid intake will dilute the salts in your urine. By doing this, you may reduce your risk of stones forming.
Diet can also affect the chance of forming a stone. One of the more common causes of calcium kidney stones is high levels of calcium in the urine. High urine calcium levels may be due to the way your body handles calcium. It is not always due to how much calcium you eat. Lowering the amount of calcium in your diet rarely stops stones from forming.
Studies have shown that restricting dietary calcium can be bad for bone health and may increase kidney stone risk. Health care providers usually do not tell people to limit dietary calcium in order to lower urine calcium. But calcium intake should not be too high.
Some medications, and calcium and vitamin C supplements, may increase your risk of forming stones. Be sure to tell your health care provider all the medications and supplements you take, as these could affect your risk of stone formation. Do not stop taking any of these unless your health care provider tells you to do so.
The chance of having kidney stones is much higher if you have a family history of stones, such as a parent or sibling.
What Are Some Common Types Of Kidney Stones?
Calcium oxalate: Calcium phosphate concretion (called a Randall’s plaque- highlighted by the arrows below), erodes through the urothelium and is a nidus for CaOx deposition.
Uric Acid Stones: Uric acid is a waste product that comes from chemical changes in the body. Uric acid crystals do not dissolve well in acidic urine and instead will form a uric acid stones
Struvite Stones: Struvite stones are not a common type of stone. These stones are related to chronic urinary tract infections (UTIs). Some bacteria make the urine less acidic and more basic or alkaline. Magnesium ammonium phosphate (struvite) stones form in alkaline urine. These stones are often large, with branches, and they often grow very fast.
Cystine Stones: Cystine is an amino acid that is in certain foods; it is one of the building blocks of protein. Cystinuria (too much cystine in the urine) is a rare, inherited metabolic disorder. It is when the kidneys do not reabsorb cysteine from the urine. When high amounts of cystine are in the urine, it causes stones to form. Cystine stones often start to form in childhood.
How are kidney stones treated?
Most stones will pass out of your body (in your urine) within three to six weeks without needing any treatment. Pain relief medications are used during this time. However, pain can be so severe that hospital admission and very strong painkillers may be needed.
If a stone doesn’t pass and blocks urine flow, causes bleeding or an infection, then it may need to be removed in hospital by one of these treatments:
• Extracorporeal Shock-Wave Lithotripsy (ESWL) – Ultrasound waves are used to break your kidney stone into smaller pieces that can pass out with your urine. It is used for stones less than 2cm in size.
• Percutaneous Nephrolithotomy – For stones larger than 2cm, a small cut is made in your back so a special instrument can remove your kidney stone.
• Endoscope Removal – A tube with a camera on the end is inserted into your urethra, passed into your bladder, and then to where your stone is located. It allows your doctor to remove your stone or break it up so it can pass more easily.
• Surgery – If none of the other methods are suitable, your stone may need to be removed using traditional surgery. This will involve making a cut in your back to access your kidney and ureter to remove your stone.