The kidneys are a pair of bean-shaped organs that are located on either side of the spine. All waste products and excess water is removed from our blood by the kidneys. In short, the kidneys act as a filter for the body. Any disease that affects the kidneys, slowly reduces their capability of filtration. Hence waste products keep accumulating in the blood. A mathematical calculation based on the age, gender and race of the person is made, that gives the Glomerular Filtration Rate(GFR); the amount of blood purification the kidney can do, with respect to time. GFR is used to determine the state of health of the kidney and whether the person is in any of the CKD stages. For a normal person, the GFR is greater than or equal to 90 mL/min. Though there are various causes that can result in chronic kidney diseases, diabetes and high blood pressure are the most common. Various other reasons also result in CKD and the type of treatment is directed towards removing the root cause. 5 Stages of CKD Stage 1: In the first stage, the GFR is equal to or greater than 90 mL/min, which is same as that of a healthy kidney. There are almost no symptoms and hence, diagnosing the condition is difficult. But it is generally recommended for patients suffering from diabetes, to undergo tests, which can give details of the amount of creatinine or urea in the blood. An increased amount of creatinine in the blood or proteins in the urine is a clear indication that a person is suffering from chronic kidney disease. Other methods used to understand the state of a person's kidney are MRI, ultrasound, X-ray and CT scan. If the problem is diagnosed at this stage, the treatment becomes relatively simpler and medication can be used to stop, retard or reverse the CKD. Stage 2: The symptoms in this stage are not identifiable, just as in the first stage. The GFR lies between 60 and 89mL/min. The diagnosis can again, be done through X-ray, MRI, ultrasound and CT-scan. Kidney dialysis is generally not required if a person is detected with kidney disease at the second stage. Stage 3: This is the stage where the symptoms start showing. The GFR falls somewhere in between 30 to 59 mL/min. The patient shows symptoms of fatigue and breath shortage. Liquids start accumulating in different parts of the body and this is visible due to the swelling of the hands and legs. Urine color of the person also shows identifiable changes. It changes to dark orange, red or brown. A person, if diagnosed at the third stage, is referred to a nephrologist, who performs various lab tests to understand the root cause of the problem and suggests the type of treatment. A person in this stage, should also consult a dietitian who would recommend a diet that best suits his condition. If a patient is suffering from polycystic kidney disease, he may experience pain at the back of his body, around the area where the kidneys are located. Stage 4: With the GFR falling further, the patient starts showing additional symptoms. With increase in urea content in the patient's blood, he normally develops a bad breath. Nausea and loss of appetite are the common symptoms of a patient going through the fourth stage of CKD. There are a variety of nerve problems and he loses his capability to concentrate. The GFR in the fourth stage, is between 15 to 29 mL/min. Hemodialysis and peritoneal dialysis are the common treatments at this stage. A kidney transplant is also recommended by many nephrologists, if the GFR is very close to 15 mL/min. Stage 5: The fifth stage can be termed as a complete kidney failure. The GFR is below 15 mL/min and in some cases, the patient may have a GFR of 0 mL/min. Headaches and change in skin color are additional symptoms that already exist in the fourth stage. With the failure of the kidneys, the urination of the patient decreases to little or almost nil. A kidney transplant is the most recommended treatment at the fourth stage of CKD, though the patient may be kept on hemodialysis or peritoneal dialysis for a certain period of time. It is always beneficial to get CKD diagnosed at the early stages. The treatment in the early stages is simpler and less expensive, but if diagnosed at the later stages, the situation can become extremely complicated.