- Anatomy and function of the urinary system
- How do you know if you have a stone?
- What causes stones?
- Conservative management of kidney stones
The urinary system consists of four pars:
- Two bean-shaped kidneys
- A triangle shaped, balloon-like organ in the lower abdomen called the bladder
- Two tubes called ureters which connect each kidney to the bladder,
- The urethra, a channel which allows urine to flow from the bladder to the outside of the body.
Each kidney is located toward the back and lateral to the spine. The lowest rib signals the midportion of the kidney.
How urine is made
After the body extracts energy from the food we eat, waste is sent into the blood. The kidneys process about fifty gallons of blood each day. Urine is produced as waste containing excess water and dissolved solids after the kidneys filter and clean blood. The kidneys also maintain a stable balance of salts and other substances in the blood. The ureters carry urine from the kidneys to the bladder, which can hold over a pint of urine. The bladder holds the urine until urination, where the urethra carries urine from the bladder out of the body.
A urinary kidney stone is a cluster of crystals which have formed in the urinary tract. Urinary stones can be described by their location as kidney stones, ureteral stones or bladder stones. The location of the stone in the urinary tract may often be determined by the location of the symptoms they are causing.
In most cases stones are initially formed in the kidney where they generally don’t cause symptoms. They may be dissolved by the presence of blood or infection in the urine on route to examination. Sometimes they can grow large enough to damage the kidney, which may cause discomfort in the back or flank area.
Generally, it is not until a kidney stone begins to pass out of the kidney and move down the ureter that patients realize they are there.
Kidney stones are hardened crystal collections of variable composition that form on the inner surface of the kidney. They may remain in the kidney or break off and travel down the urinary tract in which case they may be referred to as ureteral or bladder stones, depending on where they are located in the urinary tract.
The cause of formation is not always known. Your diet can affect stone formation. The kidneys must maintain the correct amount of water in the body while removing waste materials. Disruption of this balance can lead to saturation of urine with small crystals that won’t dissolve. Such crystals can adhere into collections and slowly add layers to form a stone. Normally, urine contains chemicals that prevent the crystals from forming. Some people may lack something that stops the stone from forming. These tiny crystals may pass out in the urine without causing pain, or if they stick to the inner surfaces of the kidney, they can grow and accumulate into large stones.
A kidney stone can grow for months or years before causing a problem or showing symptoms. Other risk factors may include age, genetic disorders, lifestyle, occupation, water consumption, obesity and climate. Scientists do not feel that eating any specific food causes stones to form in healthy individuals, even though certain food may promote formation of stones in susceptible people.
Depending on what chemicals are present, kidney stones can vary in color. They are usually yellow or brown, but can be tan, gold, or black. They also vary in texture, size and shape. Stones can be round or jagged and can be as small as sand particles to as big as golf balls.
Anyone can get kidney stones. Usually, there is a family history of stones. Kidney stones development can be associated with conditions such as urinary tract blockage, recurrent urinary infections, and inflammatory bowel disease.
Urinary stones can damage the kidney and urinary tract. Therefore, elimination of stones is necessary. Fortunately, almost 70 percent to 80 percent of all kidney stones pass spontaneously.
Sometimes drinking plenty of water assists in the passage of the stone by itself. A patient may stay home and take pain medication as needed; the doctor will ask to save the passed stone for analysis. Over 90 percent of stones that are less than 4 mm in size will pass spontaneously. Thus, patients with smaller stones are usually recommended to try and pass their stone with the aid of hydration and pain medication as needed. For patients who do not pass stones on their own, there is minimally invasive surgery available to remove the stones.
Learn more about kidney stone treatments and procedures.