A build-up of calcium in the kidneys, urinary tract infection and the production of excess urine acid can all lead to kidney stones. A stone as small as a grain of rice can be as painful as one the size of a golf ball, with hydration level, urine composition and medical history all coming into play. The time it takes for a stone to develop is different in each person. For some, stones can form in a matter of months; in others it takes several years.
There are four types of kidney stones:
Calcium stones that form from excess calcium that builds up in the kidneys and urine. As many as 85 per cent of kidney stones fall into this category.
Uric acid stones that form when the acid level in the urine gets too high. Most experts blame genetics when this occurs.
Struvite stones that form when a urinary tract infection upsets the chemical balance in the urine and allows added bacteria to form.
Cystine stones that form when too much of this amino acid is present in the urine. In most people, the excess cystine production is a genetic problem that generally requires long-term treatment.
While it's possible to have kidney stones and never know it, most people experience extreme back and side pain. This occurs when more and more stones move into the tube that connects the kidney and bladder, called the ureter. Other common symptoms include urine that's bloody, burns or smells bad; a persistent need to urinate, nausea and vomiting; and, if stones accompany a urinary tract infection, fever and chills.
If you suspect you have kidney stones, contact your doctor. Although drinking extra clear fluids is often enough to help most people pass a stone, your doctor will want to make sure no residue is left behind. Stone fragments left in the urinary tract can serve as a foundation for others to form. To help relieve pain during a kidney stone attack, non-prescription pain medications like acetaminophen or ibuprofen may be prescribed. However, if the pain is too severe, the stone too large or if several stones are blocking the urinary tract, shock waves may be used to break up large stones into smaller ones that can be more easily passed. In rare cases, surgery is used to remove stones through a small cut in the back, or through a thin tube inserted into the urinary tract.
Risks and Recurrence
Unfortunately, kidney stones have a high recurrence rate. Other risk factors include being overweight; not drinking enough daily fluids; eating a high-protein, high-sodium, low-calcium diet; living a sedentary lifestyle; having high blood pressure; and having undergone gastric bypass surgery. Kidney stones are also common in those with Inflammatory Bowel Disease and chronic diarrhoea.
Drinking lots of water is the best prevention. Experts, in fact, recommend those with a history of stones to drink as much as 4,376ml glasses a day. People who have suffered calcium stones may also need to limit their intake of chocolate, beets, spinach and rhubarb. Those who have suffered an acid-related stone may be advised to eat less meat or, if kidney stones has become a chronic problem, take medications that help keep urine acid levels under control.
- Mayo Clinic
- Harvard Medical School Family Health Guide; President and Fellows of Harvard College; 1999