Kidney Function and Dialysis: Understanding When It Becomes Necessary

Chronic kidney disease is common in elderly patients, often developing silently without symptoms until function is significantly impaired. Many families discover their parent has kidney disease only when it has progressed to the stage where dialysis is needed. Understanding kidney function, how disease develops, and when dialysis becomes necessary helps families make informed decisions about their parent's care.

How the Kidneys Work

The kidneys filter waste products from blood and produce urine. Normal kidney function involves:

• Filtering blood to remove urea, creatinine, and other waste products
• Regulating fluid balance and blood pressure
• Producing hormones that stimulate red blood cell production and bone health
• Reabsorbing nutrients (glucose, amino acids) back into the bloodstream

Each kidney contains about one million filtering units (nephrons). Kidney disease develops when nephrons are damaged, reducing filtering capacity.

Measuring Kidney Function

Kidney function is measured by glomerular filtration rate (GFR):

GFR 90 or higher: Normal kidney function

GFR 60-89: Mild reduction in kidney function, usually asymptomatic, requires monitoring

GFR 30-59: Moderate to severe reduction, symptoms may develop (fatigue, swelling, anemia)

GFR 15-29: Advanced kidney disease, symptoms significant, dialysis preparation begins

GFR below 15: End-stage renal disease (ESRD), dialysis or transplant essential for survival

GFR is calculated from serum creatinine, age, sex, and race. Your parent's doctor will track GFR over time.

Causes of Chronic Kidney Disease in Elderly

Diabetes (30% of cases): High blood glucose damages the kidney's filtering units over years.

Hypertension (25% of cases): High blood pressure damages kidney blood vessels.

Glomerulonephritis (10-15% of cases): Inflammation of the kidney's filtering units, sometimes autoimmune.

Chronic pyelonephritis: Recurrent kidney infections damage kidney tissue.

Polycystic kidney disease: Inherited condition causing cysts throughout the kidneys.

Blockage: Kidney stones, prostate enlargement, or tumors block urine flow.

Medications: Certain medications (NSAIDs, ACE inhibitors in some settings, some antibiotics) can damage kidneys.

In many elderly patients, the cause is unclear (presumed hypertension and/or diabetes).

Symptoms of Advanced Kidney Disease

In early stages, kidney disease is asymptomatic. As GFR falls below 30, symptoms develop:

• Fatigue and weakness (from anemia; the kidneys produce less erythropoietin hormone)
• Shortness of breath (from fluid accumulation in lungs)
• Swelling in legs and feet (from fluid retention)
• Nausea and loss of appetite
• Itching (from uremia; waste products accumulate in blood)
• Difficulty concentrating (uremia affects brain)
• High blood pressure (worse than usual)
• Muscle cramps
• Polyuria at night (frequent nighttime urination)

When Is Dialysis Necessary?

Dialysis is considered when:

GFR falls below 15: At this stage, kidneys filter less than 15% of normal. Waste accumulation causes symptoms. Dialysis is becoming necessary.

Uremic symptoms develop: Severe nausea, persistent itching, encephalopathy (confusion), or other uremic symptoms indicate dialysis is needed.

Metabolic derangement: Severe electrolyte abnormalities (high potassium, low sodium) or acid-base disturbance that cannot be managed with medication.

Fluid overload: Swelling and shortness of breath from fluid accumulation that cannot be managed medically.

Nutritional decline: Patient cannot maintain adequate nutrition due to uremia and nausea.

The decision to start dialysis is collaborative, considering your parent's overall health, symptom severity, and preferences.

Types of Dialysis

Hemodialysis: Blood is filtered outside the body by an artificial kidney machine.

• Typically 3-4 times weekly, 4 hours per session
• Blood is accessed through a fistula (surgically created connection between artery and vein in forearm) or catheter
• During dialysis, waste is removed and fluid balance is corrected
• Advantages: efficient, well-established, can schedule around activities
• Disadvantages: significant time commitment, dietary restrictions, fluid restrictions

Peritoneal dialysis: The peritoneum (lining of the abdomen) acts as a natural filter.

• Solution is instilled into the abdomen through a catheter; wastes diffuse into the solution
• Solution is drained and replaced multiple times daily (manual) or by machine overnight (automated)
• Advantages: gentler, allows more independence, flexible scheduling
• Disadvantages: continuous treatment required, risk of peritonitis (infection), less efficient than hemodialysis for large patients

Nocturnal hemodialysis: 5-6 nights per week, 6-8 hours per session, either at center or at home.

• Advantages: fewer restrictions, less fluid weight gain between sessions
• Disadvantages: significant time commitment, requires trained partner or home setup

Pre-Dialysis Preparation

When GFR falls below 20, preparation for dialysis begins:

Vascular access creation: For hemodialysis, a fistula is surgically created 2-3 months before dialysis is expected to begin. This allows time for the fistula to mature and develop adequate blood flow.

Education: Your parent and family learn about dialysis options, dietary modifications, and medication management.

Dietary counseling: Nephrologist works with dietitian to prepare your parent for dietary restrictions: limited potassium, phosphorus, sodium, and fluid.

Medication review: Some medications are adjusted or stopped as kidney function declines. Dose adjustments are necessary for medications excreted by kidneys.

Psychosocial assessment: Social worker assesses your parent's emotional adjustment, home support, and coping strategies.

Life on Dialysis

Dietary changes:

• Limited potassium: avoidance of bananas, oranges, potatoes, tomatoes (high potassium can cause dangerous heart rhythm)
• Limited phosphorus: avoidance of dairy, nuts, seeds
• Limited sodium: a low-salt diet, no processed foods
• Limited fluid: between sessions, weight gain should not exceed 3-5 kg (excess water cannot be removed by kidneys)

Medication management:

• Many medications are adjusted for kidney disease
• Some medications are toxic to failing kidneys and must be avoided
• Phosphate binders are taken with meals to bind phosphorus

Work and activity:

• Hemodialysis: 3-4 half-days per week are spent in dialysis center; work may be difficult to maintain
• Peritoneal dialysis: more flexible, allows work continuation more easily
• Travel: dialysis can be arranged at other centers; discuss with nephrologist in advance

Monitoring:

• Regular blood tests (monthly or more often) to monitor electrolytes, nutritional status, and other markers
• Regular dialysis adequacy testing to ensure the dialysis prescription is optimal
• Regular blood pressure checks
• Regular weight checks

Complications of Dialysis

Vascular access complications (hemodialysis):

• Thrombosis: fistula clots, requiring intervention
• Infection: fistula infections are serious, requiring antibiotics or surgery
• Steal syndrome: insufficient blood flow to hand; occurs in small percentage of patients

Peritonitis (peritoneal dialysis):

• Infection of the peritoneum; causes abdominal pain and fever
• Treated with antibiotics through the dialysate
• Repeated infections may force switch to hemodialysis

Cardiovascular complications:

• Dialysis patients have higher risk of heart attack and stroke
• Fluid imbalance can cause blood pressure swings
• Cardiac problems are monitored closely

Anemia: Kidneys produce less erythropoietin; anemia develops and is treated with medication.

Bone disease: Phosphorus and calcium imbalances affect bone health; medications are used to maintain balance.

Infections: Dialysis patients have higher infection risk; influenza and pneumococcal vaccinations are recommended.

Dialysis Adequacy and Quality of Life

Quality of life on dialysis varies significantly:

Factors affecting quality:

• Patient's acceptance and adaptation
• Quality of vascular access (for hemodialysis)
• Adequacy of dialysis prescription
• Family and social support
• Presence of other chronic conditions
• Motivation to follow dietary and fluid restrictions

For families managing dialysis alongside other chronic conditions, see our guide to managing chronic conditions in elderly parents, which includes strategies for coordinating multiple specialists and managing medication interactions with dialysis.

Most dialysis patients:

• Continue working or maintaining activities
• Have reasonable energy levels
• Can travel and maintain social relationships
• Live for years on dialysis
• Some eventually become candidates for kidney transplant

For families in Kochi coordinating dialysis appointments and follow-up care, our hospital companion service handles appointment transport, communication with the dialysis unit, and ensures medication adherence between sessions.

Kidney Transplantation

For suitable candidates, kidney transplantation is an option:

Advantages: Better quality of life, fewer dietary restrictions, longer survival than dialysis, return to more normal activities.

Requirements: Younger age (typically under 65), reasonable overall health, absence of cancer or active infection, willingness to take immunosuppressive medications lifelong.

Sources: Living donor (family, friend, altruistic donor) or deceased donor (waiting list).

Outcome: Transplanted kidney functions for an average of 10-20 years, then may fail (returning to dialysis).

Your parent's nephrologist can discuss transplant candidacy if appropriate.

Palliative Approach: Conservative Management Without Dialysis

Some elderly patients with advanced kidney disease choose not to pursue dialysis:

Palliative approach: Focus on symptom management, comfort, and quality of life without dialysis.

Appropriate for:

• Patients with very limited life expectancy (< 6 months)
• Patients with significant dementia or unable to consent
• Patients who value shorter remaining life with greater independence over prolonged life on dialysis

Median survival without dialysis: 5-10 weeks after GFR falls below 5, but varies widely.

This approach is supported by palliative care specialists; the nephrologist can facilitate discussion if your parent expresses this preference.

Managing Emotional Impact

Starting dialysis is a life-changing event. Many patients experience:

• Anxiety about dialysis needles
• Depression and grief over loss of independence
• Frustration with dietary and fluid restrictions
• Anger at the disease

Families can help:

• Acknowledge the difficulty of the transition
• Connect with other dialysis patients for peer support
• Encourage participation in rehabilitation programs
• Support adherence to diet and fluid restrictions
• Celebrate milestones and improvements

For families managing kidney disease and dialysis care for elderly parents remotely, our Kochi companion service arranges nephrologist appointments, assists with dietary modifications, supports dialysis compliance, and coordinates vascular access creation.

This article is for informational purposes only. Decisions about dialysis should be made with your parent's nephrologist. For our editorial standards, see our editorial policy.