About 1 in 10 American adults will experience kidney stones at some point in their life. Men are more likely to develop kidney stones than women and some 2 million Americans are seen in emergency rooms every year for stones in the kidneys and urinary tract. Approximately half of all patients with kidney stones will experience a recurrence about 10 years after the first episode.
How do Kidney Stones Form
Most kidney stones are made up of calcium. Uric acid comprise the majority of the remaining stones. Other substances like ammonium acid urate, cystine and xanthine may also make up kidney stones. Most of the time the urine becomes saturated. Substances within the urine, like calcium and uric acid, then precipitate. It compresses together to form a stone. Sometimes stones may form in the bladder rather than the kidney.
Read more on urinary stones.
The exact reason why kidney stones form can be complex. In most instances it is a matter of there being excessively high quantities of the substances mentioned above within the urine. This can either be due to the presence of high quantities of these substances within the body or specifically being passed out in the urine. Alternatively, it can also be a result of very low water levels in the body where urine is more concentrated than normal.
This is more likely to occur when there is a high dietary intake of certain substances that can form urine stones and dehydration are major risk factors for kidney stones. A family history, previous history of kidney stones, obesity and certain medical conditions may also increase the likelihood of kidney stones forming. Most of the stones that form in the kidney are small and quickly pass out. However, it may obstruct anywhere along the course of the urinary tract.
How to Spot Kidney Stones
With so many different organs lying in the abdominal cavity, particularly in and around the kidneys, it is not surprising that the symptoms of kidney stones are sometimes misdiagnosed for other conditions. Furthermore kidney stones are often asymptomatic when it is still in the kidneys and may only cause symptoms once it leaves the kidneys and enter the ureter. Even then there may be little to no symptoms if the stones are small.
These small stones can pass out of the urinary system with the urine and may never be noticed. However, larger stones may not only cause symptoms like pain when urinating but it may also become stuck in the urinary tract. It can block the flow of urine and lead to complications, some of which may be serious. These complications may further account for some of the symptoms seen with more severe cases of kidney stones.
The kidney lies in the upper abdomen, towards the back on either side of the torso. This area is commonly referred to as the flank. Depending on which side the kidney stone is located, there may be flank pain on that side only. Stones in both kidneys are rare. The pain can travel down the side of the abdomen along the course of the ureter and to the pelvis and groin where the bladder and urethra are located. Often the pain is described as coming in waves and it becomes intense before gradually easing. This is also known as renal colic.
Another common symptom is pain when urinating. This may or may not be accompanied by symptoms like difficult or limited urine flow. The pain may be isolated to the pelvis, below the umbilicus (belly button) where the baldder is located. It may also extend from the flanks, where the kidneys are located, down to the pelvis where the bladder is located and even to the groin. Once the pain starts, it tend to worsen over hours. It is often described as a colicky pain but can also be a sharp and stabbing pain.
Changes in Urine
Normally urine is clear to a pale yellow in color. If water intake is low then urine may be a darker yellow color but it tends to be transparent to translucent. With a kidney stone the urine may appear cloudy and can also be unusual in color, such as a pink, brown or red in color. Gross blood in the urine is uncommon with kidney stones. Furthermore the characteristic ammonia smell of urine may be superimposed by a foul smell.
A person may urinate anywhere between 6 to 8 times in a day. Some people may urinate more often, and others less frequently but these differences are considered to be normal. However, with kidney stones there may be frequent urination. Sometimes a person may have to urinate a short while after passing urine. Depending on the location and size of the stone, the volume of urine may also be lower than normal.
Urge to Urinate
Another symptom that may occur with kidney stones is a person may experience a persistent urge to urinate even after passing urine. Sometimes very little urine is passed out upon subsequent evacuations. Even urination may sometimes not ease the urge. The persistent urge to urinate usually correlates with frequent urination. At other times a person may experience a strong urge but cannot pass any urine.
Difficulty Passing Urine
Voiding (the act of urinating) can be difficult apart from the pain when passing urine. A person may have a strong urge to urinate but have to strain to pass urine. Depending on the location of the kidney stone, only small amounts of urine may be passed out or sometimes none at all. Sometimes a person is anxious to urinate due to the pain and may therefore resist the urge to urinate or not want to urinate forcefully.
Other Signs and Symptoms
Read more on kidney stone tests.
Although medical attention is always advised for symptomatic kidney stones, there are times where emergency medical attention is necessary. Any of these symptoms may warant a visit to the emergency room.
- Severe pain which is persistent and/or worsening beyond a few hours.
- Gross blood in the urine where the urine will appear fully red in color.
- High fever that is not resolving along with other kidney stone symptoms.
- Persistent nausea and vomiting that hampers eating and rehydration.
If left untreated, larger urine stones can cause many serious complications which can even become life threatening in some instances. Always speak to a doctor when kidney stones are suspected or if the symptoms are worsening after diagnosis and once treatment is commenced.