The kidneys are essentially regulatory organs that maintain the volume and composition of body fluid by filtration of the blood and selective reabsorption or secretion of filtered solutes. the kidneys are retroperitoneal organs (ie located behind the peritoneum) situated on the posterior wall of the abdomen on each side of the vertebral column, at about the level of the twelfth rib. The left kidney is slightly higher in the abdomen than the right, due to the presence of the liver pushing the right kidney down. The kidneys take their blood supply directly from the aorta via the renal arteries; blood is returned to the inferior vena cava via the renal veins. Urine (the filtered product containing waste materials and water) excreted from the kidneys passes down the fibromuscular ureters and collects in the bladder. The bladder muscle (the detrusor muscle) is capable of distending to accept urine without increasing the pressure inside; this means that large volumes can be collected (700-1000ml) without high-pressure damage to the renal system occurring. When urine is passed, the urethral sphincter at the base of the bladder relaxes, the detrusor contracts, and urine is voided via the urethra.
On sectioning, the kidney has a pale outer region of the cortex and a darker inner region of the medulla. The medulla is divided into 8-18 conical regions, called the renal pyramids; the base of each pyramid starts at the corticomedullary border, and the apex ends in the renal papilla which merges to form the renal pelvis and then on to form the ureter. In humans, the renal pelvis is divided into two or three spaces the major calyces which in turn divide into further minor calyces. The walls of the calyces, pelvis, and ureters are lined with smooth muscle that can contract to force urine towards the bladder by peristalsis. The cortex and the medulla are made up of nephrons; these are the functional units of the kidney, and each kidney contains about 1.3 million of them.
Kidney (renal) disease can cause fluid and waste buildup, which can be potentially deadly. Kidney disease can be caused by diabetes, infections, high blood pressure, hepatitis, and other conditions. Symptoms include swelling, frequent urination, dry skin, fatigue, and many other signs. Treatments for renal disease include medications (to control other conditions that can cause kidney disease), dialysis, and kidney transplants.
- Pyelonephritis (Infection Of Kidney Pelvis): Bacteria may infect the kidney, usually causing back pain and fever. A spread of bacteria from an untreated bladder infection is the most common cause of pyelonephritis.
- Glomerulonephritis: An overactive immune system may attack the kidney, causing inflammation and some damage. Blood in the urine and kidney failure are common symptoms of glomerulonephritis.
- Kidney Stones (Nephrolithiasis): Minerals in urine form crystals (stones), which may grow large enough to block urine flow. It’s considered one of the most painful conditions. Most kidney stones pass on their own but some are too large and need to be treated.
- Nephrotic Syndrome: Damage to the kidneys causes them to spill large amounts of protein into the urine. Leg swelling (edema) may be a symptom.
- Polycystic Kidney Disease: A genetic condition resulting in large cysts in both kidneys that impair their function.
- Acute Renal Failure (kidney failure): A sudden worsening in kidney function. Dehydration, a blockage in the urinary tract, or kidney damage can cause acute renal failure, which is usually reversible.
- Chronic Renal Failure: A permanent partial loss of kidney function. Diabetes and high blood pressure are the most common causes.
- End-Stage Renal Disease (ESRD): Complete loss of kidney function, usually due to progressive chronic kidney disease. People with ESRD require regular dialysis for survival.
- Papillary Necrosis: Severe damage to the kidneys can cause chunks of kidney tissue to break off internally and clog the kidneys. If untreated, the resulting damage can lead to total kidney failure.
- Diabetic Nephropathy: High blood sugar from diabetes progressively damages the kidneys, eventually causing chronic kidney disease. Protein in the urine (nephrotic syndrome) may also result.
- Hypertensive Nephropathy: Kidney damage caused by high blood pressure. Chronic renal failure may eventually result.
- Kidney Cancer: Renal cell carcinoma is the most common cancer affecting the kidney. Smoking is the most common cause of kidney cancer.
- Interstitial Nephritis: Inflammation of the connective tissue inside the kidney, often causing acute renal failure. Allergic reactions and drug side effects are the usual causes.
- Minimal Change Disease: A form of nephrotic syndrome in which kidney cells look almost normal under the microscope. Steroids are used to treat minimal change disease, which can cause significant leg swelling (edema).
- Nephrogenic Diabetes Insipidus: The kidneys lose the ability to concentrate the urine, usually due to a drug reaction. Although it’s rarely dangerous, diabetes insipidus causes constant thirst and frequent urination.
- Renal cyst: A benign hollowed-out space in the kidney. Isolated kidney cysts occur in many normal people and almost never impair kidney function.
- Urinalysis: A routine test of the urine by a machine and often by a person looking through a microscope. Urinalysis can help detect infections, inflammation, microscopic bleeding, and kidney damage.
- Kidney ultrasound: A probe placed on the skin reflects sound waves off the kidneys, creating images on a screen. Ultrasound can reveal blockages in urine flow, stones, cysts, or suspicious masses in the kidneys.
- Computed Tomography (CT scan): A CT scanner takes a series of X-rays and a computer creates detailed images of the kidneys.
Nephrectomy: Surgery to remove a kidney. A nephrectomy is performed for kidney cancer or severe kidney damage.
- Magnetic Resonance Imaging (MRI scan): A scanner uses radio waves in a magnetic field to make high-resolution images of the kidneys.
- Urine and Blood Cultures: If an infection is suspected, cultures of the blood and urine may identify the bacteria responsible. This can help target antibiotic therapy.
- Ureteroscopy: An endoscope (flexible tube with a camera on its end) is passed through the urethra into the bladder and ureters. Ureteroscopy generally cannot reach the kidneys themselves but can help treat conditions that also affect the ureters.
- Kidney Biopsy: Using a needle inserted into the back, a small piece of kidney tissue is removed. Examining the kidney tissue under a microscope may help diagnose a kidney problem.
- Antibiotics: Kidney infections caused by bacteria are treated with antibiotics. Often, cultures of the blood or urine can help guide the choice of antibiotic therapy.
- Nephrostomy: A tube (catheter) is placed through the skin into the kidney. Urine then drains directly from the kidney, bypassing any blockages in urine flow.
- Lithotripsy: Some kidney stones may be shattered into small pieces that can pass in the urine. Most often, lithotripsy is done by a machine that projects ultrasound shock waves through the body.
- Nephrectomy: Surgery to remove a kidney. A nephrectomy is performed for kidney cancer or severe kidney damage.
- Dialysis: Artificial filtering of the blood to replace the lost function of damaged kidneys.
- Hemodialysis: A person with complete kidney failure is connected to a dialysis machine, which filters the blood and returns it to the body. Hemodialysis is typically done three days per week in people with ESRD.
- Peritoneal Dialysis: Placing large amounts of a special fluid in the abdomen through a catheter, allows the body to filter the blood using the natural membrane lining the abdomen. After a while, the fluid with the waste is drained and discarded.
- Kidney transplant: Transplanting a kidney into a person with ESRD can restore kidney function. A kidney may be transplanted from a living donor or a recently deceased organ donor.
Chronic Kidney Disease
Chronic kidney disease may sometimes be prevented by controlling the other diseases or factors that can contribute to kidney disease. People who have already developed kidney failure also need to focus on these things to prevent the complications of kidney failure.
- Keep your blood pressure below 130/80. Learn to check your blood pressure at home.
- If you have diabetes, keep your blood sugar within a target range. Talk with your doctor about how often to check your blood sugar.
- Stay at a healthy weight. This can help you prevent other diseases, such as diabetes, high blood pressure, and heart disease.
- Control your cholesterol levels.
- Don’t smoke or use other tobacco products. Smoking can lead to atherosclerosis, which reduces blood flow to the kidneys and increases blood pressure.
What to avoid
- Avoid taking medicines that can harm your kidneys. Be sure that your doctor knows about all prescription drugs, over-the-counter drugs, and herbs you are taking.
- Avoid dehydration by promptly treating illnesses, such as diarrhea, vomiting, or fever, that cause it. Be especially careful when you exercise or during hot weather.
- Avoid products containing magnesium, such as antacids like Mylanta or Milk of Magnesia or laxatives like Citroma. These products increase your risk of having abnormally high levels of magnesium (hypermagnesemia), which may cause vomiting, diarrhea, or both.
- Control your cholesterol levels.
- Avoid X-ray tests that require IV dye (contrast material), such as an angiogram, an intravenous pyelogram (IVP), and some CT scans. IV dye can cause more kidney damage. Make sure that your doctor knows about any tests that you are scheduled to have.
Kidney Stones – What Happens
A kidney stone begins as a tiny piece of crystal in the kidney. When the urine leaves the kidney, it may carry the crystal out, or the crystal may stay in the kidney. If the crystal stays in the kidney, over time more small crystals join it and form a larger kidney stone.
Most stones leave the kidney and travel through the urinary tract when they are still small enough to pass easily out of the body. No treatment is needed for these stones.
Larger stones may become stuck in the tubes that carry urine from the kidney to the bladder (ureters). This can cause pain and possibly block the urine from flowing to the bladder and out of the body. The pain often becomes worse over 15 to 60 minutes until it is severe. The pain may ease when the stone no longer blocks the flow of urine, and it often goes away when the stone passes into the bladder. Medical treatment is often needed for larger stones.
- The smaller the stone, the more likely it is to exit the body (pass) on its own. Only 1 or 2 out of 10 kidney stones need more than home treatment.
- The average time a stone takes to pass ranges from 1 to 3 weeks, and two-thirds of stones that pass on their own pass within 4 weeks of when the symptoms started.
- Almost half of all people who get kidney stones will get more stones within 7 years unless they take preventive measures.
Problems that may occur with kidney stones include:
- An increased risk of urinary tract infection, or making an existing urinary tract infection worse.
- Kidney damage, if stones block the flow of urine out of both kidneys (or out of one kidney, for people who have a single kidney). For most people with healthy kidneys, kidney stones do not cause serious damage until they completely block the urinary tract for 2 weeks or longer.
Kidney stones are more serious for people who have a single kidney or an impaired immune system or have had a kidney transplant.
Stones in pregnant women
When stones occur during pregnancy, an obstetrician and urologist should determine whether you need treatment. Treatment will depend on your trimester of pregnancy.
For small stones, most people don’t need any treatment other than taking pain medicine and drinking enough fluids.
Treatment for your first stone
If your doctor thinks the stone can pass on its own, and if you feel you can deal with the pain, he or she may suggest home treatment, including:
- Using pain medicine: Nonprescription medicine, such as nonsteroidal anti-inflammatory drugs (NSAIDs), may relieve your pain. Your doctor can prescribe stronger pain medicine if needed.
- Drinking enough fluids: You’ll need to keep drinking water and other fluids when you are passing a kidney stone.
If your pain is too severe, if the stones are blocking the urinary tract or if you also have an infection, your doctor will probably suggest a medical procedure, such as lithotripsy, or surgery to deal with the stone. For more information, see Other Treatment and Surgery.
Preventing future stones
After you have had a kidney stone, you are more likely to have one again. Almost half of all people who have a stone will have more stones within 7 years unless they take preventive measures.
You may be able to prevent getting more kidney stones by drinking more fluids and making changes in your diet. Talk with your doctor or a dietitian if you need help with your diet. If you have risk factors (things that put you at risk) for having more stones, such as a family history of stones, your doctor may suggest medicines that help prevent stones from forming.
Herbs for kidney health
- Gokshura powder
- Shilajit powder
What can I do to help stay healthy?
- Keep your blood pressure below 130/90 and maintain healthy levels of cholesterol.
- It’s important to have your cholesterol levels checked regularly.
- Lead a healthy lifestyle and maintain a healthy weight.
- Eat a balanced healthy diet low in saturated fats.
- Become a nonsmoker.
- If you have diabetes make sure you actively treat your blood glucose.
Healthy Eating: The food you eat plays a huge role in the health and well-being of your body. It can help to prevent some diseases and to manage others. As well as providing the body with a variety of nutrients, food choices can also help in weight reduction and weight control.
- Eat healthy foods: with as many fresh ingredients as possible.
- Don’t overeat: always leave a meal feeling like you could eat a little bit more.
- Eat breakfast: a good breakfast activates your metabolism first thing in the morning.
- Avoid fat diets: they are hard to maintain over a long period and can create or worsen ill health.
- Drink plenty of fluids: choose to drink water instead! Sugary drinks have lots of calories, while caffeine and alcohol are both diuretics and can leave the body dehydrated.
- Check nutrition panels on all parceled foods you buy: choose only foods that list a low percentage of sugar and salt and that is low in saturated fats.