The kidneys are two bean-shaped organs, each about the size of a fist. They are located just below the rib cage, one on each side of the spine.
Each kidney is made up of about a million filtering units called nephrons. A nephron has two parts. The glomerulus strains blood cells and large molecules from the toxins and fluid. The fluids and toxins that pass through then go through the tubule. The tubule collects minerals that the body needs and puts them back into the bloodstream and filters out more toxins. The final product becomes urine.
Every day, the kidneys filter about 120 to 150 quarts of blood to produce about 1 to 2 quarts of urine, composed of wastes and extra fluid. The urine flows from the kidneys to the bladder through two thin tubes of muscle called ureters, one on each side of the bladder. The bladder stores urine. The muscles of the bladder wall remain relaxed while the bladder fills with urine. As the bladder fills to capacity, signals sent to the brain let a person know it’s time ‘to go’. When the bladder empties, urine flows out of the body through a tube called the urethra, located at the bottom of the bladder. In men the urethra is long, while in women it is short.
The kidneys also make hormones. These hormones help regulate blood pressure, make red blood cells and promote bone health.
Problems with your kidneys can be short-term or long term concern. From kidney stones to kidney failure, it’s important to know more about healthy kidney function.
Kidney stones are small, hard mineral deposits that form inside your kidneys. The stones are made of mineral and acid salts. Kidney stones form when your urine contains more crystal-forming substances — such as calcium, oxalate and uric acid — than the fluid in your urine can dilute.
Pyelonephritis is an inflammation of the kidney, usually due to a bacterial infection. In the majority of cases, the infection starts within the bladder and then migrates up the ureters and into the kidneys.
Interstitial nephritis is when the spaces between the kidney tubules become inflamed. This inflammation causes the kidneys to swell.
Glomerulonephritis produces inflammation in the glomeruli. Damaged and inflamed glomeruli may not filter the blood properly.
Nephrosis is any degenerative disease of the renal tubules. Nephrosis can be caused by kidney disease, or it may be secondary to another disorder, particularly diabetes.
Renal (Kidney) Failure
Kidney failure occurs when the kidneys fail to adequately filter waste products from the blood. Kidney failure can be divided into two categories: acute kidney injury or chronic kidney disease.
Acute kidney injury (AKI), previously called acute renal failure, is a rapidly progressive loss of renal function. AKI can result from a variety of causes. Dialysis may be necessary to bridge the time gap required for treating these fundamental causes.
Chronic kidney disease (CKD) develops slowly and, initially, shows few symptoms. CKD can be the long term consequence of irreversible acute disease or part of a disease progression. The most common causes of CKD are diabetes mellitus and long-term, uncontrolled hypertension. Polycystic kidney disease is another known cause of CKD. The majority of people afflicted with polycystic kidney disease have a family history of the disease. Other genetic illnesses affect kidney function, as well.
Chronic kidney failure is measured in five stages, which are calculated using a patient’s GFR, or glomerular filtration rate.
- Stage 1 is mildly diminished renal function, with few overt symptoms.
- Stages 2 and 3 need increasing levels of supportive care from their medical providers to slow and treat their renal dysfunction.
- Stages 4 and 5 usually require preparation of the patient towards active treatment in order to survive.
- Stage 5 is considered a severe illness and requires some form of dialysis or kidney transplant.
Keep your kidneys healthy
Keep fit and active: Keeping fit helps to reduce your blood pressure and therefore reduces the risk of Chronic Kidney Disease.
Keep regular control of your blood sugar level: About half of people who have diabetes develop kidney damage, so it is important for people with diabetes to have regular tests to check their kidney functions.
Monitor your blood pressure: Although many people may be aware that high blood pressure can lead to a stroke or heart attack, few know that it is also the most common cause of kidney damage.
Eat healthy and keep your weight in check: This can help prevent diabetes, heart disease and other conditions associated with CKD. Reduce your salt intake. The recommended sodium intake is 5-6 grams of salt per day (around a teaspoon).
Maintain a healthy fluid intake: Although clinical studies have not reached an agreement on the ideal quantity of water and other fluids we should consume daily to maintain good health, traditional wisdom has long suggested drinking 1.5 to 2 liters of water per day. Consuming plenty of fluid helps the kidneys clear sodium, urea and toxins from the body which, in turn, results in a “significantly lower risk” of developing chronic kidney disease.
Do not smoke: Smoking slows the flow of blood to the kidneys. When less blood reaches the kidneys, it impairs their ability to function properly. Smoking also increases the risk of kidney cancer by about 50 percent.
Do not take over-the-counter pills on a regular basis: Common drugs such non-steroidal anti-inflammatory drugs like ibuprofen are known to cause kidney damage and disease if taken regularly. Such medications probably do not pose significant danger if your kidneys are relatively healthy and you use them for emergencies only, but if you are dealing with chronic pain, such as arthritis or back pain, work with your doctor to find a way to control your pain without putting your kidneys at risk.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)