CKD affects about 35.5 million people in the United States, which is approximately 14% of the population. It often goes undetected and undiagnosed until the condition is well advanced.
African American, Hispanic, Native American, and Asian American people have a greater chance of developing CKD than people who are white. This may be due to disparities in the primary care of People of Color.
As kidney disease advances, dangerous levels of waste can rapidly build up inside the body. Treatment aims to stop or slow the progression of kidney dysfunction by controlling the underlying cause.
Read on to learn more about CKD, including its causes, symptoms, and treatments.
People who are at high risk of developing CKD should have regular kidney function checks. Early detection can help prevent severe kidney damage.
What is CKD?
CKD is a slow and gradually progressive condition that causes kidney dysfunction. However, if one kidney stops functioning correctly, the other may still carry out normal functions.
A kidney may deteriorate to a certain level of dysfunction and not get any worse. Sometimes, however, the condition may progress to kidney failure.
Most people with CKD are not aware that they have it because symptoms do not usually develop in the early stages of the condition. Typically, by the time a person notices any symptoms, the condition is at an advanced stage. Damage to the kidneys is irreversible.
How to recognize CKD
Symptoms of CKD can include:
- hypertension, or high blood pressure
- anemia
- edema, or swollen feet, hands, and ankles
- fatigue, or tiredness
- decreased urine output
- bloody urine, in some cases
- dark urine, in some cases
- decreased mental alertness, when the condition is severe
- aย loss of appetite
- persistentย itchy skin, when the condition is severe
- moreย frequent urination, especially at night, in some cases
Doctors use glomerular filtration rate (GFR) to determine how advanced a personโs CKD is. The GFR shows how well a personโs kidney is filtering waste. A personโs GFR can depend on their body size, sex, and age.
A doctor can determine a personโs GFR by testing the levels of creatinine in their blood. Creatinine is a waste product of creatine, which is an acid that helps supply energy to muscle cells.
When the kidneys are working correctly, they filter a relatively constant amount of creatinine from the blood. Changes in blood creatinine levels can indicate that a person has a problem with their kidneys.
A change in a personโs GFR allows a doctor to classify CKD into stages, as follows.
Stage 1
Stage 1 CKD means that a personโs GFR is at least 90 milliliters per minute (ml/min) per 1.73 meters squared (m2). This is normal kidney function but with evidence of kidney damage. Some signs of kidney damage in stage 1 CKD can include protein in a personโs urine or physical damage.
Stage 2
If a person has stage 2 CKD, their GFR is 60โ โ89 ml/min per 1.73 m2. A GFR in this range usually means that a personโs kidneys are working well. However, this GFR indicates that a person with stage 2 CKD has additional signs of kidney damage. These signs can include physical damage to the kidney or protein in a personโs urine.
A person with stage 1 or 2 CKD can speak with a doctor about medications that can help protect their kidneys.
Stage 3
At stage 3 CKD, a personโs GFR is 30โ โ59 ml/min per 1.73 m2. This range indicates that a person has some damage to the kidneys. A personโs kidneys are not working as well as they should at stage 3 CKD.
Stage 3 CKD can be separated into two subcategories:
- Stage 3a:ย Stage 3a means that a person has a GFR of 45โ โ59 ml/min per 1.73 m2.
- Stage 3b:ย Stage 3b means that a person has a GFR of 30โ โ44 ml/min per 1.73 m2.
Although most people with stage 3 CKD do not have symptoms, some may experience:
- swelling in the hands and feet
- lower back pain
- more frequent urination
- anemia
- high blood pressure
- bone disease
A person with stage 1โ3 CKD may be able to slow the damage to their kidneys by:
- controlling their blood sugar, if they haveย diabetes
- controlling their blood pressure
- eating a healthy diet
- not smoking or using tobacco
- being active for 30 minutes per day, 5 days per week
- maintaining a moderate weight
- meeting with a kidney doctor, or nephrologist
A person with stage 3 CKD may also want to speak with a dietitian about following a healthy diet. Additionally, a person with stage 3 CKD can speak with a doctor about angiotensin converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs). These medications can lower blood pressure and may help prevent CKD from worsening.
Stage 4
By stage 4 CKD, a personโs GFR is 15โ29 ml/min per 1.73 m2. At this stage, a personโs kidneys are moderately to severely damaged. Stage 4 CKD is a serious condition and the last stage before a person develops kidney failure.
A person with stage 4 CKD is more likely to experience symptoms such as swollen hands and feet, back pain, and more frequent urination. Complications such as anemia or bone disease are also more likely.
A doctor may recommend that a person with stage 4 CKD speak with a nephrologist or dietitian.
Stage 5
A person with stage 5 CKD has a GFR of 15 ml/min per 1.73 m2 or less. At this stage, a personโs kidneys have either failed or are close to failing.
Symptoms of kidney failure include:
- itching
- muscle cramps
- nausea
- vomiting
- swelling in the hands and feet
- back pain
- more frequent urination
- difficulty sleeping
- difficulty breathing
- decreased urine output
If a person has kidney failure, they will need to undergo dialysis or have a kidney transplant to survive. Kidney dialysis helps filter a personโs blood when their kidneys are no longer able to.
It is essential that people receive an early diagnosis of and prompt treatment for kidney disease to prevent serious damage.
People with diabetes should have an annual test, which measuresย microalbuminuriaย โ or small amounts of protein โ in urine. This test can detect earlyย diabetic nephropathy, which is kidney damage linked to diabetes.
