CKD Stages
If your doctor has told you that you are at risk for chronic kidney disease you may be wondering how it is diagnosed. This article will help you understand what to look for and expect before and after you are diagnosed.
Your kidney’s main function is to filter out extra fluid, toxins, and waste from your body through urine. Other functions that your kidneys perform to keep your body healthy are balancing electrolytes and minerals in your blood. While also making hormones to manage blood pressure, make red blood cells, and maintain good bone health. Your kidneys play many roles in keeping you healthy without you even noticing. [1]
Chronic kidney disease (CKD) is the slow progression of decreased kidney function over time. As your kidney function decreases, all of the key roles described above start to become affected and you may start to experience symptoms. As your kidney function significantly worsens, as measured by lab results, it is called kidney failure. At the point of kidney failure, the treatment options are dialysis or a kidney transplant. [1]
Now that you know how the disease progresses, you can understand that the sooner you know you have kidney disease, the more time you have to make changes to prolong your kidney function.
What Causes Kidney Disease?
Diabetes
Uncontrolled blood sugars over time cause damage to your kidneys. One of the signs that you have kidney disease as a result of diabetes is having protein in your urine. [1]
High Blood Pressure
High blood pressure over time can damage the blood vessels in your kidneys and decrease function. [1]
Heart Disease
More research is showing a relationship between kidney disease and heart disease. Medical conditions that are classified as heart disease include coronary heart disease, arrhythmia, congestive heart failure, congenital heart disease, and more. [1]
Family History
If you have a family history you may be at risk of getting kidney disease. It is common for kidney disease to run in families. [2]
Whether you meet some or none of these risk factors, it is important for you to share your medical history with your doctor, go to regular appointments, and maintain good health to prevent kidney disease.
- 15% of adults in the U.S. or an estimated 37 million people have CKD
- CKD is predominant in people aged 65 years or older
- CKD is common in non-Hispanic Black (16%), White (13%), and Asian (13%) adults
- CKD in Hispanics is 14% [2]
Other Causes of CKD:
- Lupus
- Substance abuse
- Polycystic kidney disease
- Anti-GBM (Goodpasture’s) disease
- Heavy metal poisoning
- Rare genetic conditions
- Hemolytic uremic syndrome in children
- IgA vasculitis
- Renal artery stenosis
CKD Symptoms
Your kidneys are resilient and it can be hard to know if you have kidney disease in the early stages. As your kidney function declines you will start to accumulate water and salt in the body causing swelling and wt gain. The best way to know if you have kidney disease is to see your doctor and have a blood and urine test. [1]
Signs and symptoms of CKD:
- Lack of appetite
- Dry skin
- Lack of urination
- Trouble sleeping
- Swelling of ankles and/or feet
- Nausea
- High blood pressure
- Shortness of breath
- Muscle cramps
- Vomiting
- Decreased concentration
- Fatigue [1]
How CKD is diagnosed
To know if you have kidney disease your doctor will take a blood and urine test. Your doctor will use these tests to monitor your kidney function and discuss a plan of care for you. Your doctor will complete two or three consecutive blood and urine tests to confirm a kidney disease diagnosis. [1]
Glomerular Filtration Rate (GFR)
This is a blood test that your doctor will look at to check for your current kidney function. The results are separated into different categories:
- A GFR of 60+ is considered normal kidney function
- A GFR <60 indicates that you have kidney disease
- A GF of <15 is considered kidney failure [1]
Creatinine
This blood test also helps your doctor determine your GFR. Creatinine is a waste product that is found naturally in your body as a result of normal muscle breakdown. The relationship between creatinine and kidney disease is that as your kidney function decreases, your creatinine will increase. [1]
Urine Test
Your doctor will have you collect a urine sample to test for a protein called albumin. As mentioned earlier a healthy kidney does not let protein pass from your body into your urine. With kidney disease, there will be some albumin in your urine.
Two types of urine tests:
- Dipstick
- Urine albumin-to-creatinine ratio (UACR)
Labs to Monitor
Once you have been diagnosed with CKD you need to see your doctor as directed to monitor your blood results. Below are labs that may be monitored by your kidney doctor.
| Test | Results | What The Results Mean |
| Urine Albumin-to-Creatinine Ration | 30 or more indicates CKD | This test checks for protein in your urine. A lower result is best. |
| Creatinine | 0.7-1.3 is normal for men0.6-1.1 is normal for women | As kidney function declines and cannot get rid of creatinine in the blood this number increases. |
| GFR (Glomerular Filtration Rate) | Less than 60 indicates CKD | This result decreases as kidney function gets worse. |
| Blood Urea Nitrogen (BUN) | Less than 20 is normal | Urea is another waste product in our body. This test checks the amount currently in your blood. |
| Blood Pressure | Pressure less than 120/80 is normal | High blood pressure can damage the blood vessels in your kidneys by making them constantly work too hard. |
| Serum Albumin | 3.4-5.0 is normal | Measuring albumin can tell us if you are eating enough. |
| Bicarbonate | >22 is normal | This test measures how acidic your blood is. |
| Sodium | 135-145 is normal | High levels can show kidney damage or dehydration. |
| Potassium | 3.5-5.0 is normal | Potassium is an electrolyte that helps your muscles and nerves work properly. Very high and very low levels are dangerous. |
| Calcium | 8.5-10.2 is normal | This mineral is checked because it can be low in people with CKD. Calcium helps to keep your bones strong. |
| Phosphorus | 2.7-4.6 is normal | This mineral is also important for your bone health. High levels can harden blood vessels and weaken your bones over time. |
| Parathyroid Hormone (PTH) | Less than 65 is normal | PTH is a hormone that regulates calcium and phosphorus. Calcium, phosphorus, and PTH all work together to maintain good bone health. |
| Vitamin D | 20 or more is normal | Vitamin D can decrease in your body with CKD. Maintaining normal levels is key for your bone health. |
| Hemoglobin A1c(For people with diabetes) | The goal is between 7-8% | This result is your average blood sugar levels over 2-3 months. |
| Cholesterol | Less than 200 is normal | High levels of cholesterol can cause heart disease which is a risk factor for CKD. |
| HDL Cholesterol | Less than 40 is normal | HDL is the good cholesterol that helps to remove fat from your arteries to keep you healthy. |
| LDL Cholesterol | Less than 100 is normal | LDL is the bad cholesterol that can block your arteries if your levels are high. |
| Triglycerides | Less than 150 is normal | Triglycerides are a type of fat that is circulating in your blood. |
| Hemoglobin (Hgb) | 12-17 is normal | People with CKD often have anemia that can cause fatigue. Low Hgb is a sign of anemia. |
Some test result ranges may change when you are on dialysis. Make sure to talk to your doctor or dietitian about what your goals are for your test results.
The Five Stages of CKD
Since CKD is a progressive disease it is classified into five stages based on your GFR. When you are diagnosed with CKD your doctor will diagnose you into a stage based on your kidney test results. [3]
Stage 1 – Glomerular Filtration Rate ≥ 90 mL/min/1.73 ㎡
In stage 1 you usually have no symptoms. Your GFR is likely normal but blood flow through your kidneys increases and may increase the size of your kidneys. Living a healthy lifestyle is key at this stage to slow the progression of the disease. As mentioned before seeing your doctor regularly and getting routine blood tests will help monitor your kidney health over time. [3]
Stage 2 – Glomerular Filtration Rate 60-90 mL/min/1.73 ㎡
Once you are considered at stage 2 you will start to see a mild decrease in your GFR and your kidneys will show some sign of damage in your kidney blood tests. You may still not have any noticeable signs or symptoms. People who are diagnosed at this stage are usually also being tested for diabetes or high blood pressure. [3]
Stage 3 – Glomerular Filtration Rate 30-59 mL/min/1.73 ㎡
At stage 3 you now have a moderate decrease in GFR and kidney damage. Your lab results will start to show protein in your urine but symptoms may still be mild. This stage can occur after 7 years of having diabetes. This is the stage where your doctor may talk to you about limiting the protein in your diet to put less strain on your kidneys. As your kidney function declines you will start to experience more health complications listed below.
- Electrolyte imbalances
- High levels of natural waste products (urea) in your blood
- High blood pressure
- Anemia
- Early bone mineral disease [3]
Stage 4 – Glomerular Filtration Rate 15-29 mL/min/1.73 ㎡
Stage 4 is considered advanced kidney damage and you will see a significant decrease in your GFR and an increase in your creatinine results. The amount of waste products accumulating in your body will rise as well as the protein in your urine. At this point you will be seeing your doctor more frequently and limiting protein in your diet is needed. The build-up of these waste products that your body cannot remove effectively starts to cause new symptoms including
- Nausea
- Changes in taste
- Changes in the smell of your breath
- Anorexia
- Difficulty concentrating
- Numbness in your fingers and toes [3]
Stage 5 – Glomerular Filtration Rate <15 mL/min/1.73 ㎡
The last stage is considered end-stage renal disease where kidney failure occurs. Your kidneys are not able to work effectively and renal replacement therapy is needed. The two forms of therapy are dialysis or a kidney transplant. Dialysis is needed weekly when your kidney function is 15% or less. Additional symptoms at this stage are listed below.
- Anorexia
- Nausea and vomiting
- Headaches
- Fatigue
- Swelling around eyes and ankles
- Muscle cramps
- Changes in skin color and pigmentation [3]
Prevention of Progression
The best next steps you can take today is to be proactive about maintaining good health. As soon as you know you are at risk see your medical providers regularly and ask questions. Be an advocate for yourself and ask about treatments or referrals to see other health professionals you may need like a dietitian or a therapist. Here are some steps you can reflect on to identify where you can start making changes to slow the progression of kidney disease.
- Manage your blood pressure
- Meet with a dietitian and start following a kidney-friendly diet
- If you have diabetes strive to meet your blood sugar goal
- Exercise regularly and maintain a healthy body weight
- Take your medications as directed by your kidney doctor
- Stop smoking as this may affect your ability to receive a transplant
- Make sure you get regularly get enough sleep
- Find healthy ways to cope with your feelings and support your mental health [1]
References
- U.S. Department of Health and Human Services. (n.d.). What is chronic kidney disease? National Institute of Diabetes and Digestive and Kidney Diseases. Retrieved June 2, 2022, from https://www.niddk.nih.gov/health-information/kidney-disease/chronic-kidney-disease-ckd/what-is-chronic-kidney-disease
- Centers for Disease Control and Prevention. (2021, March 4). Chronic kidney disease in the United States, 2021. Centers for Disease Control and Prevention. Retrieved June 2, 2022, from https://www.cdc.gov/kidneydisease/publications-resources/ckd-national-facts.html
- Escott-Stump, S. (2015). Chronic Kidney Disease and Renal Failure. In Nutrition and diagnosis-related care (pp. 888–896). essay, Wolters Kluwer.
- National Institutes of Health. (2013, February). Your Kidney Test Results. National Institute of Diabetes and Digestive and Kidney Diseases .
- Cole, N. I., Suckling, R. J., Desilva, V., He, F. J., MacGregor, G. A., & Swift, P. A. (2019). Serum sodium concentration and the progression of established chronic kidney disease. Journal of nephrology, 32(2), 259–264. https://doi.org/10.1007/s40620-018-0541-z
