Kidneys are essential to having a healthy body. They filter waste products such as ammonia, urea, uric acid, creatine, and amino acids from the blood. They also help remove excess water and salt from the body. Apart from excretion, kidneys also play an essential role in regulating electrolyte balance, blood pressure, and red blood cell production. Keep reading to the end to learn everything that you need to know about kidney stones.
What are Kidney Stones
Kidney stones are one of the most common kidney diseases. They are hard deposits of salts and minerals that form in the kidney or anywhere in the urinary tract. Statistics are showing that kidney stones affect approximately five to ten percent of the developed world’s population.
Many of us know that kidney stones can be intensely painful. But very few people know why and how they are formed. Keep reading to the end to find answers to one of the most searched health questions.
The Human Anatomy
To find out why and how kidney stones form, let us first review the human anatomy. The human body has two kidneys, one on each side of the spine. Each of the two kidneys has approximately two million functional units known as nephrons. These nephrons are responsible for the removal of waste products, water, electrolytes, and metabolites. Depending on the body’s needs, nephrons can either take these ingredients back to the blood or discard them as urine.
Kidney stone is a multifactorial disease. There is no exact cause of kidney stones, but there are several factors that may increase your risk.
How Kidney Stones Form
Kidney stones form when the urine is high in crystal-forming products such as calcium, uric acid, and oxalate than the fluid in urine can dilute. The lack of products that inhibit crystal formation in the urine also creates an enabling environment for the formation of kidney stones.
Types of Kidney Stones and Their Causes
There are several types of kidney stones. Knowing the type of kidney stones can help you determine the best way to address the problem and lower the chances of getting more stones. The known types of kidney stones include:
1. Calcium stones
They are the most common and are usually in the form of calcium oxalate. Oxalate is one of the substances in urine that cause crystal formation. The body gets oxalate from the liver and can also absorb it from the diet. Some of the foods that are high in oxalates include:
- Cocoa powder
- Cashews and almonds
- Miso soup
Apart from diet, other factors that can increase the concentration of calcium and oxalates in the urine include:
- Metabolic disorders
- Vitamin D supplements
- Intestinal Bypass surgeries
Apart from calcium oxalates, calcium kidney stones can also occur in the form of calcium phosphate. Metabolic conditions such as renal tubular acidosis are the leading cause of the formation of calcium phosphate stones. Medications to treat seizures and migraines such as Qudexy XR and Topamax can also increase the risk.
High sodium levels in the blood can also cause kidney stones. High sodium levels cause excess calcium exchange in the renal tubules, which can cause mineralization.
2. Uric acid stones
Uric acid kidney stones are common in people who have high uric acid levels in the blood and urine. These stones are crystalline and radiolucent. They appear black in a radiographic image. A high protein diet is one of the leading causes of high uric levels in the blood. Some drugs such as probenecid can also increase the risk of uric acid stones. Diets and medicines that lower urine PH levels to below 5.5 can also cause uric acid stones.
3. Struvite stones
Struvite kidney stones are big and multiheaded. They form when magnesium, phosphate, and ammonia crystalize and stick together inside kidneys. These stones can grow big enough to occupy and block the entire renal pelvis. Because of their large size and sharp shape, struvite kidney stones manifest themselves as blood in the urine (hematuria).
These stones usually arise or form during and after a bacterial infection. That is because some bacterias breakdown urea into nitrogen that increases the PH levels of urine. When the urine becomes alkaline, it starts causing precipitation of struvite stones.
4. Cystine stones
The most common cause of cystine stones is a hereditary disorder known as cystinuria. The disorder causes an error of reabsorption. People with this disorder lack a transporter to carry protein Cysteine. As a result, this protein builds up in the filtered urine and ends up causing crystalline cysteine stones. These stones are recurrent and don’t respond well to surgery.
Cystine stones form at low urinary PH levels. Conditions like metabolic acidosis that can lower the urine PH levels can worsen the problem.
1. Family History and Genetics
People who have family members suffering from kidney stones are at a higher risk of developing stones, too. Some inborn errors of metabolism or enzyme deficiency can lead to the formation of kidney stones. People who high levels of calcium and uric acid in their blood are also at a higher risk. People who have had one or more kidney stones before are at risk of developing another one.
People with a large waistline, high body mass index (BMI), and those experiencing weight gain are at risk of kidney stones. According to a study published in the US National Library of Medicine National Institutes of Health, women weighing more than 220 pounds (100 Kgs) are 90 percent more likely to develop kidney stones.
Kidney stones form when urine has more crystal-forming substances than the available fluids can dilute. Not drinking enough water can trigger kidney stones. People living in dry and warm climates who sweat a lot and don’t drink enough water are at a higher risk than others.
Eating diets high in sugar, salt, and proteins can increase the risk of developing some types of kidney stones. Diets rich in sodium increase the amount of calcium that kidneys filter and increase the risk of some types of kidney stones.
5. Digestive disease and surgery
Inflammatory bowel disease, chronic diarrhea, and gastric bypass surgeries can cause changes in the digestive tract and affect the absorption of calcium, electrolytes, and water. That increases the amount of crystal-forming products in urine. Hyperparathyroidism repeated urinary tract infections, cystinuria, and renal tubular acidosis can also increase the risk.
Diagnosing Kidney Stones
Analysis of passed stones
When you pass a kidney stone, you should preserve it and take it to your doctor for analysis. Your doctor will send the sample to the lab to determine the specific type of kidney stones you are passing. Lab results will reveal the type of the stone and help your doctor determine the cause. They will also help the doctor know how to prevent the formation of more stones.
If you are not passing a kidney stone, but your doctor suspects that you have a kidney stone, he may request the following tests and procedures:
A blood test can reveal whether you have too much uric acid or calcium or both in your blood. Your doctor can use your blood test results to monitor the health of your kidneys.
A urine test can reveal whether you have too many crystal-forming products and too few substances that inhibit stone formation.
High-speed or dual energy computerized tomography (CT) can show kidney stones in the urinary tract. An ultrasound is the fastest and the easiest way to diagnose kidney stones. X-rays are less effective than CT and ultrasound because they are likely to miss small kidney stones.
Treating Kidney Stones
The best treatment option for kidney stones depends on the type and cause. Small stones that have minimal symptoms can be treated by:
Drinking 6 glasses of water and above can help dilute and prevent kidney stones from forming. If you are not passing clear or nearly clear urine, you should increase your water intake. The more water you drink, the lower your risk of kidney stones.
2. Medical therapy
Some medications can help you pass kidney stones. These medications work by relaxing the muscles of the ureter to help you pass kidney stones with less or no pain.
3. Pain relievers
Passing kidney stones can be extremely painful. Your doctor may recommend pain relievers like naproxen sodium and ibuprofen.
Treating large kidney stones
Large kidney stones cause symptoms like blood in the urine. These stones can damage the kidney and cause an infection. Procedures to remove large kidney stones include:
1. Sound waves
If you have a large kidney stone in a location where surgery might be too risky, your doctor will recommend extracorporeal shock wave lithotripsy (ESWL). ESWL creates vibrations that break a large stone into small and tiny pieces. These pieces are easy to pass in the urine.
ESWL takes 40 to 60 minutes and requires light anesthesia. It causes moderate pain, but your doctor may put you under sedation to make you patient. An ESWL can cause blood in the urine, bleeding around the kidney and nearby organs, bruising on the back, and discomfort when passing the tiny stones.
It involves the use of a thin lighted tube equipped with a camera (telescope) to remove small kidney stones in the kidney and ureter. The doctor inserts the ureteroscope through the urethra and bladder to the ureter. After locating the stone, the doctor will then use a small tool to break the crystals into small pieces that can easily pass in your urine.
Your doctor can perform surgery to remove a large kidney stone. The doctor will put you under general anesthesia and then make a small incision in your back. The doctor then inserts a small instrument equipped with a camera through the small incision. This surgery is only an option when ESWL isn’t working.
4. Parathyroid gland surgery
Kidney stones caused by an overactive parathyroid gland can’t stop until the primary problem is fixed. If this is your case, your doctor may recommend parathyroid gland surgery.
Kidney Stones Prevention
You can lower your risk of developing kidney stones through a combination of some medications and lifestyle changes. Some of the lifestyle changes that can help reduce your risk of kidney stones include:
1. Stay hydrated
If you are from a family with a history of kidney stones, your doctor will recommend drinking enough water to pass approximately two liters of urine every day. People living in a warm and dry climate and those who exercise also need to increase their water intake until they are able to pass light and clear urine.
Choosing non-animal protein sources and reducing your salt and sugar intake can lower the risk of kidney stones. You can also switch to using salt substitutes like Mrs. Dash.
Restricting foods that are high in oxalates can also help. Some of the foods that are high in oxalates include:
- soy products
- black pepper
Calcium is essential for healthy bones. Lack of calcium can cause low bone density. To prevent kidney stones while keeping bone density in check, you should continue eating calcium-rich foods like sardines and pilchards but avoid calcium supplements. Only avoid calcium-rich foods if your doctor advises you otherwise.
3. Lemon juice
Lemon juice contains citrate. This chemical can prevent calcium kidney stones from forming. It can also break them into smaller crystals that are easy to pass. Lemon juice can also provide you with vitamin C and also inhibit bacteria growth.
To make the perfect lemon juice for kidney stones, add freshly squeezed lemon to a glass of water. You should drink as much as you want. The more lemon juice you drink, the better, but even one glass per day can help.
4. Celery juice
Many doctors recommend celery juice to people who are at risk of kidney stones. That is because this juice has the potential to clear out toxins that contribute to kidney stone formation. It can also help pass kidney stones if you already have them.
You should avoid celery juice if you have:
- low blood pressure
- bleeding disorder
- a scheduled surgery
People taking sedative medications, isotretinoin, lithium, and levothyroxine should also avoid this juice.
5. Dandelion root juice
Dandelion juice can help improve digestion and increase urine output. You can either buy it as tea or make your own fresh juice. If you are making your own juice, remember to add apple, ginger, and orange peel for taste. You can drink two to three cups per day. Do not drink this juice if you are taking:
- blood thinners
If you are at a high risk of developing kidney stones, your doctor might recommend some medications that can help control the amount of salt, calcium, phosphate, and other minerals in the urine. The type of medication will depend on the specific type of kidney stones you have or at a high risk of developing.
When to see your doctor
You should see your doctor when you start passing stones. You should also seek immediate doctor’s attention if you are experiencing the following symptoms:
- blood in urine
- severe pain