The main function of the kidneys is to remove waste products and excess water from the blood. The kidneys process about 200 liters of blood every day and produce about two liters of urine. The waste products are generated from normal metabolic processes including the breakdown of active tissues, ingested foods, and other substances. The kidneys allow consumption of a variety of foods, drugs, vitamins and supplements, additives, and excess fluids without worry that toxic by–products will build up to harmful levels. The kidney also plays a major role in regulating levels of various minerals such as calcium, sodium, and potassium in the blood.
1.As the first step in filtration, blood is delivered into the glomeruli by microscopic leaky blood vessels called capillaries. Here, blood is filtered of waste products and fluid while red blood cells, proteins, and large molecules are retained in the capillaries. In addition to wastes, some useful substances are also filtered out. The filtrate collects in a sac called Bowman's capsule and drains into the tubule.
2.The tubules are the next step in the filtration process. The tubules are lined with highly functional cells which process the filtrate, reabsorbing water and chemicals useful to the body while secreting some additional waste products into the tubule.
The kidneys also produce certain hormones that have important functions in the body, including the following:
1.Activate form of vitamin D (calcitriol or 1,25 dihydroxy–vitamin D), which regulates absorption of calcium and phosphorus from foods, promoting formation of strong bone.
2.Erythropoietin (EPO), which stimulates the bone marrow to produce red blood cells.
3.Renin, which regulates blood volume and blood pressure.
2.Erythropoietin (EPO), which stimulates the bone marrow to produce red blood cells.
3.Renin, which regulates blood volume and blood pressure.
What is the difference between kidney failure and kidney disease?
Kidney failure
1.Kidney failure occurs when the kidneys partly or completely lose their ability to carry out normal functions.
2.This is dangerous because water, waste, and toxic substances build up that normally are removed from the body by the kidneys.
3.It also causes other problems such as anemia,high blood pressure, acidosis (excessive acidity of body fluids), disorders of cholesterol and fatty acids, and bone disease in the body by impairing hormone production by the kidneys
Chronic kidney disease
Chronic kidney disease is when one suffers from gradual and usually permanent loss of kidney function over time. This happens gradually over time, usually months to years. Chronic kidney disease is divided into five stages of increasing severity (see Table 1 below). Stage 5 chronic kidney failure is also referred to as end–stage renal disease, wherein there is total or near–total loss of kidney function and patients need dialysis or transplantation to stay alive. The term "renal" refers to the kidney, so another name for kidney failure is "renal failure." Mild kidney disease is often called renal insufficiency.
Unlike chronic kidney disease, acute kidney failure develops rapidly, over days or weeks.
Acute kidney failure usually develops in response to a disorder that directly affects the kidney, its blood supply, or urine flow from it.
Acute kidney failure usually does not cause permanent damage to the kidneys. With appropriate treatment of the underlying condition, it is often reversible, with complete recovery.
In some cases, though, it may progress to chronic kidney disea
In some cases, though, it may progress to chronic kidney disea
10 Symptoms of Kidney Disease
Symptom 1: Changes in Urination
Kidneys make urine, so when the kidneys are failing, the urine may change. How?
1.You may have to get up at night to urinate.
2.Urine may be foamy or bubbly. You may urinate more often, or in greater amounts than usual, with pale urine.
3.You may urinate less often, or in smaller amounts than usual with dark colored urine.
4.Your urine may contain blood.
5.You may feel pressure or have difficulty urinating.
Kidneys make urine, so when the kidneys are failing, the urine may change. How?
1.You may have to get up at night to urinate.
2.Urine may be foamy or bubbly. You may urinate more often, or in greater amounts than usual, with pale urine.
3.You may urinate less often, or in smaller amounts than usual with dark colored urine.
4.Your urine may contain blood.
5.You may feel pressure or have difficulty urinating.
Symptom 2: Swelling
Failing kidneys don't remove extra fluid, which builds up in your body causing swelling in the legs, ankles, feet, face, and/or hands.
Symptom 3: Fatigue
Healthy kidneys make a hormone called erythropoietin (a-rith'-ro-po'-uh-tin) that tells your body to make oxygen-carrying red blood cells. As the kidneys fail, they make less erythropoietin. With fewer red blood cells to carry oxygen, your muscles and brain become tired very quickly. This condition is called anemia, and it can be treated.
Symptom 4: Skin Rash/Itching
Kidneys remove wastes from the bloodstream. When the kidneys fail, the buildup of wastes in your blood can cause severe itching.
Symptom 5: Metallic Taste in Mouth/Ammonia Breath
A buildup of wastes in the blood (called uremia) can make food taste different and cause bad breath. You may also notice that you stop liking to eat meat, or that you are losing weight because you just don't feel like eating.
Symptom 6: Nausea and Vomiting
A severe buildup of wastes in the blood (uremia) can also cause nausea and vomiting. Loss of appetite can lead to weight loss.
Symptom 7: Shortness of Breath
Trouble catching your breath can be related to the kidneys in two ways. First, extra fluid in the body can build up in the lungs. And second, anemia (a shortage of oxygen-carrying red blood cells) can leave your body oxygen-starved and short of breath.
Symptom 8: Feeling Cold
Anemia can make you feel cold all the time, even in a warm room.
Symptom 9: Dizziness and Trouble Concentrating
Anemia related to kidney failure means that your brain is not getting enough oxygen. This can lead to memory problems, trouble with concentration, and dizziness.
Symptom 10: Leg/Flank Pain
Some people with kidney problems may have pain in the back or side related to the affected kidney. Polycystic kidney disease, which causes large, fluid-filled cysts on the kidneys and sometimes the liver, can cause pain.
Kidney Transplantation
Purpose
Kidney transplantation surgically places a healthy kidney from another person into your body. The donated kidney does enough of the work that your two failed kidneys used to do to keep you healthy and symptom free.
How Kidney Transplantation Works
A surgeon places the new kidney inside your lower abdomen and connects the artery and vein of the new kidney to your artery and vein. Your blood flows through the donated kidney, which makes urine, just like your own kidneys did when they were healthy. The new kidney may start working right away or may take up to a few weeks to make urine. Unless your own kidneys are causing infection or high blood pressure, they are left in place.
Kidney transplantation.
Getting Ready
The transplantation process has many steps. First, talk with your doctor because transplantation isn’t for everyone. You could have a condition that would make transplantation dangerous or unlikely to succeed.
You may receive a kidney from a deceased donor—a person who has recently died—or from a living donor. A living donor may be related or unrelated—usually a spouse or a friend. If you don’t have a living donor, you’re placed on a waiting list for a deceased donor kidney. The wait for a deceased donor kidney can be several years.
The transplant team considers three factors in matching kidneys with potential recipients. These factors help predict whether your body’s immune system will accept the new kidney or reject it.
1.Blood type. Your blood type (A, B, AB, or O) must be compatible with the donor’s. Blood type is the most important matching factor.
2.Human leukocyte antigens (HLAs). Your cells carry six important HLAs, three inherited from each parent. Family members are most likely to have a complete match. You may still receive a kidney if the HLAs aren’t a complete match as long as your blood type is compatible with the organ donor’s and other tests show no problems with matching.
3.Cross-matching antigens. The last test before implanting an organ is the cross-match. A small sample of your blood will be mixed with a sample of the organ donor’s blood in a tube to see if there’s a reaction. If no reaction occurs, the result is called a negative cross-match, and the transplant operation can proceed.
Diet for Kidney Transplantation
1.Diet for transplant patients is less limited than it is for dialysis patients, although you may still have to cut back on some foods. Your diet will probably change as your medicines, blood values, weight, and blood pressure change.
2.You may need to count calories. Your medicine may give you a bigger appetite and cause you to gain weight.
3.You may have to eat less salt. Your medications may cause your body to retain sodium, leading to high blood pressure.
Kidney transplantation has advantages and disadvantages. See the list below.
Pros
+ A transplanted kidney works like a normal kidney.
+ You may feel healthier and “more normal.”
+ You have fewer diet restrictions.
+ You won’t need dialysis.
+ Patients who successfully go through the selection process have a higher chance of living a longer life.
Cons
- It requires major surgery.
- You may need to wait for a donor.
- Your body may reject the new kidney, so one transplant may not last a lifetime.
- You’ll need to take immunosuppressants, which may cause complications