What Your Kidneys Actually Do
Before understanding kidney disease, it helps to appreciate how much your kidneys quietly accomplish every day. These two fist-sized organs, positioned on either side of your spine just below the rib cage, filter roughly 200 liters of blood daily — removing waste products and excess fluid as urine, regulating blood pressure, balancing electrolytes such as potassium and sodium, and stimulating red blood cell production. They also help maintain bone strength by activating a form of vitamin D.
When kidney function declines gradually over time, that collection of tasks becomes less efficient. Waste builds up in the bloodstream, fluid balance is disrupted, and the effects eventually ripple across other body systems. Understanding this interconnectedness is the foundation for making sense of a CKD diagnosis.
Chronic Kidney Disease (CKD)
A long-term, gradual loss of kidney function that develops over months or years and does not fully reverse, but can often be slowed with treatment.
GFR (Glomerular Filtration Rate)
A blood-test-derived number that estimates how efficiently your kidneys filter waste; it is the main measure used to determine CKD stage.
Nephrologist
A doctor who specializes in diagnosing and managing kidney diseases; typically involved in care from moderate CKD stages onward.
Creatinine
A waste product produced by normal muscle activity; elevated creatinine in the blood is one sign that kidneys are not filtering efficiently.
Proteinuria
The presence of excess protein in urine, which can signal that the kidney's filtering system is damaged and is an early marker of CKD.
Renal Dietitian
A registered dietitian with specialized training in kidney disease who helps patients adjust their diet to reduce strain on the kidneys at each stage of CKD.
Understanding the Stages of CKD
CKD is classified into five stages using a measurement called GFR — glomerular filtration rate. This number, derived from a routine blood test, estimates how much blood your kidneys filter per minute. A GFR of 90 or above with no signs of kidney damage is generally considered normal; a GFR below 15 indicates kidney failure.
- Stage 1 (GFR ≥ 90): Kidney damage is present (detected by protein in urine, for example), but filtration function is normal or slightly elevated.
- Stage 2 (GFR 60–89): Mild reduction in function, often with no symptoms.
- Stage 3a/3b (GFR 30–59): Moderate reduction; complications such as anemia or mineral imbalances may begin to appear.
- Stage 4 (GFR 15–29): Severe reduction; planning for potential kidney replacement therapy typically begins.
- Stage 5 (GFR < 15): Kidney failure; dialysis or a transplant may be required to sustain life.
Most seniors diagnosed with CKD are in stages 2 or 3, and many never progress beyond that with consistent care. To understand how a chronic condition like this differs from short-term illness, see our explanation of chronic conditions in later life.
Why CKD Is Common in Older Adults
Age itself causes some natural decline in kidney function — GFR typically falls modestly after age 40. But CKD is not simply a consequence of getting older. The two leading causes in US adults are diabetes and high blood pressure (hypertension), both of which are more prevalent in seniors and both of which damage the small blood vessels inside the kidneys over time.
Other contributing factors include heart disease, recurrent urinary tract infections, certain medications (especially long-term use of non-steroidal anti-inflammatory drugs), and a family history of kidney disease. Because so many of these factors coexist in older adults, CKD frequently appears alongside other chronic conditions — a pattern explored in our piece on daily routines that support multiple chronic conditions.
CKD Often Has No Early Symptoms
Most people with stage 1, 2, or early stage 3 CKD feel completely well, which is why the condition is sometimes called a 'silent' disease. Do not wait for symptoms before discussing kidney health with your doctor. If you have diabetes, high blood pressure, or a family history of kidney disease, ask specifically whether routine kidney function screening is appropriate for you.
What General Care Typically Involves
CKD management is not one-size-fits-all, but general approaches typically focus on slowing progression and protecting overall health. Your care team may address several areas:
- Blood pressure control: Keeping blood pressure within a target range is one of the most evidence-supported ways to slow CKD progression.
- Blood sugar management: For those with diabetes, maintaining stable glucose levels helps protect kidney tissue.
- Medication review: Some drugs, supplements, and contrast agents used in imaging can stress the kidneys; your doctor should know everything you take.
- Dietary guidance: A renal dietitian can tailor advice on sodium, protein, potassium, and phosphorus to your specific stage — general dietary advice from the internet may not apply to your situation.
- Fluid intake: Recommendations vary; some people with CKD are advised to stay well hydrated, while others need to limit fluids depending on their stage and symptoms.
- Physical activity: Gentle, consistent movement supports cardiovascular and metabolic health relevant to kidney disease management.
This article provides general health information only and is not a substitute for personalized medical advice. Always consult your healthcare provider about your specific situation.
Bring a Medication List to Every Appointment
Many common over-the-counter products — including certain pain relievers and antacids — can affect kidney function or interact with CKD medications. A complete, up-to-date list of everything you take, including supplements and vitamins, helps your care team make safe decisions. Review it together at each visit.
Working Effectively with Your Care Team
A diagnosis of CKD typically means working with more than one clinician. Your primary care provider coordinates overall care, while a nephrologist — a physician who specializes in kidney disease — may become involved from stage 3 onward. A renal dietitian, pharmacist, and social worker are also common members of a kidney-care team.
Coming to appointments prepared makes a meaningful difference. Bring a current list of all medications and supplements, note any symptoms you have noticed (fatigue, swelling, changes in urination), and write down your questions in advance. Ask specifically what your current GFR is, what stage you are in, and what the care goals are for the next period.
For a broader look at how to balance self-management with specialist involvement, our article on self-management versus specialist-led care offers practical perspective. Living well with CKD is achievable — and staying informed is one of the most powerful tools you have.
