A majority of incidents of kidney stones are found in women during their 50s. Rarely, during the final stages of pregnancy (about 1 in 1,500 cases), these stones may be formed. Otherwise, issues like obesity, family history, lifestyle, etc., play a major role in their formation.
What are Kidney Stones?
Kidney stones are nothing but the concentration of the minerals and acid salts that are found in the urine.
How are Kidney Stones Formed?
The main function of the kidney is to filter all the waste materials and the extra water present in the body, which the body secretes in the form of urine. When the urine is extremely concentrated, it starts to become crystallized and binds together to form stones. These stones form in the kidney, and can also pass to the ureter (the tubes which drain the urine from the kidney to the bladder), and the bladder, which stores the urine.
Kidney stones are also known as renal lithiasis, nephrolithiasis, and renal calculi. However, the terms ureterolithiasis, cystolithiasis, and urolithiasis are also used as all these conditions lead to stones in the urinary tract. According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), reportedly more than 3,00,000 people go to the emergency room for kidney stones, making it one of the most common problems related to the urinary tract.
Types of Kidney Stones
There are different types of kidney stones depending upon the components that they contain. Also, the size of the stones may vary. They can be as small as a rice grain, or as big as the size of a golf ball. Bigger stones cause more pain compared to the smaller ones. The stones may also have different shapes and textures, varying from being smooth to uneven.
Mentioned below is a list of the common types of kidney stones found.
In women, the most common type of stone formed is the struvite stone. These stones are usually formed due to infections, especially Urinary Tract Infection, which is found mostly in females. These can cause a lot of discomfort as they have the potential to increase in size.
The main cause of the formation of these stones is a genetic disorder known as cystinuria. In this disorder, the amino acid 'cystine' present in the kidneys, tends to seep into the urine, thereby crystallizing it and forming stones. Having a family history of cystinuria makes a person prone to stones in the kidney.
These stones are the ones that are most commonly found. There are two kinds under this category - calcium oxalate stones and calcium phosphate stones. Calcium oxalate stones are a result of concentration of oxalate (a substance found in foods naturally) and high levels of calcium. Calcium phosphate stones are the concentration of alkaline urine with a high amount of calcium.
Uric Acid Stones
Uric acid is the result of the metabolism of purines, which is a substance found in food items such as fish, meats, mushrooms, anchovies, shellfish, etc. High levels of uric acid present in the body can cause formation of these stones.
What Causes Kidney Stones in Women?
Kidney Stone Susceptibility in Women
Women are less susceptible to kidney stones as compared to men. This is because of their physiology. Women tend to have an increased percentage of citrate in their urine which prevents the formation of kidney stones to a certain extent. Studies also reveal that the male hormone 'testosterone' tends to elevate the levels of uric acid and oxalate in the body, which aggravates the chances of developing kidney stones.
Another theory that makes men more prone to this disorder is the fact that they tend to consume more food items such as animal protein including red meat, due to their bigger size, muscle mass, and appetite, when compared to women. With more amount of urine being filtered through the kidneys, along with the extra waste components that are consumed by the body, men excrete more waste materials from their body than women. Therefore, it is likely that the presence of excessive waste materials present in the body can begin to crystallize and lead to the formation of stones. Nonetheless, mentioned below are some of the major causes that can lead to the formation of kidney stones in a woman's body.
Urinary Tract Infection (UTI)
Women are more susceptible to UTIs as compared to men, which makes them prone to develop kidney stones known as struvite stones. These stones are known to develop as a result of the presence of the bacteria that has led to an infection in the urinary system, and the waste products containing byproducts of the excessive protein consumed through the food.
Pregnancy causes a lot of changes in a woman's body. There is an increase in the amount of calcium in the body during this phase. Also, the increase in the size of the uterus decreases the bladder's capacity to store the urine, thereby resulting in less intake of fluids. The hormonal increase in the levels of progesterone causes a decrease in the rate at which the urine is passed. All these factors can lead to the formation of kidney stones. However, the point to be noted is that there are very few (1 in 1,500) pregnancies that are affected by this condition.
Obesity and Dietary Habits
Women (or men) with a large waist size, and who fall under the category of an obese BMI range, are more prone to develop kidney stones as compared to those who maintain a healthy weight. Dietary habits play a major role in your weight. Consumption of food items that are high in sodium, animal protein, calcium, vitamin D, and sugar may cause kidney stones. There is an extra pressure on the kidneys to filter these components, thereby increasing the risk of the formation of kidney stones.
Lack of consumption of fluids makes the urine more concentrated, thereby increasing the risk to become crystallized and form stones. People who do not drink adequate amount of water, or healthy fluids, or who drink alcohol, can develop stones. Alcohol makes the body dehydrated because it increases the need to urinate more than normal. Also, if you eat a diet rich in sodium, sugar, high protein, but do not keep your body well hydrated, kidney stones can occur.
Some people are more prone to dehydration than others. For example, people who live in geographical areas which are more humid, need to drink more fluids than normal. Also, people who are involved in strenuous activities need to make sure that they replace the fluid that they have lost through perspiration.
Certain Health Problems
There are various health conditions associated with kidney stones. These include disorders such as:
- Cystinuria - Presence of amino acid 'cystine' in the urine.
- Hypercalciuria - Presence of excessive calcium in the urine.
- Hyperoxaluria - Presence of excessive oxalate in the urine.
- Hyperparathyroidism - Excessive secretion of hormone from the parathyroid glands present in the neck thereby releasing extra calcium in the blood.
- Renal Tubular Acidosis - Presence of excessive acid in the blood due to the kidney's inability to filter and excrete the acids through the urine.
- Hyperuricosuria - Presence of excessive levels of uric acid in the urine.
- Other health conditions like gout, undergoing chemotherapy, gastrointestinal tract surgery, cystic kidney diseases, chronic diarrhea, etc., can make one susceptible to the formation of stones.
- Also, if you have a family history of kidney stones then that makes you fall under the risk zone. Another point to be kept in mind is that kidney stones can form again and again. Therefore, taking precautionary measures are important.
Certain medications including diuretics, antacids containing calcium, a protease inhibitor named Crixivan used to treat HIV, and Topamax, an anti-seizure medication.
Recent studies show that global warming can also increase the occurrence of kidney stones. A study by Brikowski and associates states that "based on the effects of global warming, the percentage of people living in areas designated as high risk for kidney stone formation would increase from 40% in 2000 to 56% by 2050, and up to 70% by 2095. This would result in a significant 'climate-related' increase in kidney stone events."
What Symptoms Indicate the Presence of Kidney Stones?
Not all cases of kidney stones are accompanied by visible symptoms. Usually, when the size of the stone is small enough, there are no symptoms and the stone passes out through the urine. However, for larger stones, the symptoms may be prominent and bothersome. Mentioned below is the list of some of the most commonly observed symptoms indicating the presence of kidney stones.
Sudden and Constant Pain
The presence of stones may cause intense pain in the side, back, groin, or the genitals. Sometimes, a cramping pain called 'renal colic' may be felt as the muscular wall of the ureter contracts in order to push the stone towards the bladder. This pain may occur in the left side or the middle of the abdomen. At times, it may also travel into the groin. The pain may be so severe that the person is unable to perform normal movements like sitting or standing.
Presence of Blood in the Urine (Hematuria)
There might be traces of blood in the urine. Sometimes it is visible, whereas at times it might be detected through a laboratory test. Blood in the urine is an indicator of damage to the lining of the ureter tissue near or inside the kidney.
This symptom occurs when the stone is in the ureter, or after the stone has left the bladder. A urinary tract infection may be accompanied by painful urination.
Pain along with Fever and Chills
Medical attention should be sought in case of fever along with pain. Appropriate medications (generally antibiotics) are prescribed.
Pain with Vomiting and Nausea
Nausea and vomiting experienced along with the pain in the abdomen, back, or sides, may be a critical situation. Seeking immediate medical attention in this case is a must.
Other symptoms like loss in appetite, profuse sweating, weakness, colored urine (pink, red, or brown), foul-smelling urine, bubbles in urine, inability to pass urine, etc., are also observed.
Suggested Treatment Options
The treatment depends upon the size of the stone. Stones that are 4 mm or smaller in size have high chances to pass through urine. However, 5 mm stones might need treatment. Stones that are very large, would mostly require medical procedures. Therefore, determining the size, cause, and type of kidney stone is important. This is done through various tests including urine and blood analysis, X-rays, CT scans, analysis of stones that have passed, etc.
Treatment for Smaller Stones
Intake of Water
Smaller stones usually do not cause any bothersome symptom. Most of the stones pass easily through your urine by drinking a lot of water. Drinking 2-3 liters of water would flush your urinary system, which can be determined by the color of your urine - which appears to be almost colorless when the body is well hydrated.
The doctors may prescribe certain medications including painkillers and alpha blockers to minimize the pain and relax the muscles of the ureter to help pass the stone with ease.
Treatment for Larger Stones
Extracorporeal Shock Wave Lithotripsy (ESWL)
In this procedure, the stone is crushed into smaller pieces using shock waves. A machine known as a lithotripter is used by the urologist, wherein, the patient is asked to lie on a table, and the shock waves are released aiming at the site of the stone. Image-testing results are used to determine the location of the stone. The waves travel through the skin and reach the stone, crushing it into smaller pieces so that the fragments can pass through the ureter. The entire process takes about 45 minutes to an hour.
The side effects of this treatment method include minor bruising on the abdomen or the back, blood in the urine, internal bleeding around the kidney and nearby organs, discomfort during the passing of the stone, etc. A slight amount of anesthesia is also used during the procedure which may cause a little discomfort.
Percutaneous Nephrolithotomy /Nephrolithotripsy
This is a procedure wherein a small incision is made on the back of the patient to insert a thin telescopic instrument known as a nephroscope. This instrument is used to locate and remove the stone from its location. If the stone is completely removed by the surgeon during the procedure, it is known as nephrolithotomy - 'nephro' means kidney, 'litho' means stone, and 'tomy' means removal. However, if the size of the stone is too big, then shock waves may be used to crush the stone, thereby removing the smaller pieces. This procedure is known as nephrolithotripsy - 'nephro' meaning kidney, 'litho' meaning stone, and 'tripsy' meaning crushed.
The side effects may include lack of judgment and coordination due to the usage of general anesthesia. The recovery time is also more than the SWL procedure. Although, the entire procedure takes about 20-45 minutes, the patient may be asked to stay in the hospital for 2-3 days, with adequate amount of rest at home. Like all other surgeries, even this procedure involves minimal risks of bleeding, infections, and injury to the kidney and the nearby organs.
This procedure is done using an instrument known as a ureteroscope. It is a long, thin telescopic instrument which is inserted into the urethra, making its way through the bladder and ureter, thereby removing the stones. This procedure is mostly done for stones in the ureter, or the bladder, hence the name - ureteroscopy. Again, if the size of the stone is large, laser energy, shock waves, or electrical energy is used to break the stone into smaller fragments so that they can be easily removed.
This procedure is also done under general anesthesia. However, the patient can go home the same day. The complications may include bleeding and infections, but the chances are minimal. Also, if the size of the stone is big and the ureter is too small, then the doctor may insert a stent for a couple of days to hold the ureter open, and the procedure would be done as scheduled.
Parathyroid Gland Surgery
This surgery is done only when the cause behind the occurrence of kidney stones is a condition known as hyperparathyroidism. There are 4 parathyroid glands, located in the neck. In hyperparathyroidism, these glands secrete excessive hormone, which in turn leads to an increase in the level of calcium in the body, thereby causing kidney stones.
A surgical procedure known as Parathyroidectomy is done to remove these glands, thereby eliminating the cause behind the kidney-stone formation. The surgery is performed under general anesthesia and may take up to 1-3 hours. You may be allowed to go home the same day, but complete healing may take approximately 1 to 3 weeks. Like all other surgical procedures, side effects may include infections and bleeding. Complete removal of parathyroid glands may also cause low levels of calcium in the body. It is necessary to discuss the pros and cons with your doctor before the surgery.
Most of the kidney stones (small size) pass on their own through the urine within 48 hours, if proper intake of fluids is administered. If you have had kidney stones in the past, chances are that they may occur again. Therefore, it is important to take preventive measures by altering your lifestyle and dietary habits. Drink plenty of fluids (lime water is known to be an effective home remedy), eat a balanced diet, moderate your intake of calcium, sodium, sugar, vitamin D, and make sure that you consult a doctor immediately whenever any discomfort is observed.
Disclaimer: This article is for informative purposes only, and should not be used as a replacement for expert medical advice.