Home Monitoring in Chronic Kidney Disease

Why home checks matter in kidney disease

• Blood pressure is both a cause and a consequence of kidney disease. Uncontrolled pressure damages the kidneys faster, and weakened kidneys raise blood pressure.
• Fluid balance is affected: the body may hold on to water and salt, leading to swelling and breathlessness, or may become dry if too much fluid is lost.
• Diabetes control protects the kidneys.
• Early infection or illness can harm the kidneys quickly in an older adult.
• Medicines are cleared differently when kidney function is low, so side effects need vigilance.

For the broader picture, see chronic kidney disease: a home care guide.

Blood pressure

Home readings help the doctor tailor treatment. Typical targets for people with CKD are often lower than for the general population, such as around 130/80 or lower if tolerated, but targets depend on age, other illnesses and whether the person faints on standing, so the nephrologist decides. Use a validated upper-arm monitor with the correct cuff; see the blood pressure monitor buying guide and cuff size and blood pressure accuracy. A common pattern is a short run of morning and evening readings before each review, or as the doctor advises. See how to measure blood pressure at home accurately and keeping a blood pressure log and what to tell the doctor.

Important arm precautions.

• Dialysis access. If your parent has an arteriovenous fistula or graft in an arm, or a dialysis catheter, do not use that arm for blood pressure checks, injections or blood tests. A cuff can damage the access. Use the other arm. Doctors may also ask to avoid the arm on which a fistula is likely to be created in future; ask the nephrologist or nurse which arm to protect.
• Swollen arms or arms with skin problems: ask the doctor.

Blood pressure can also change around dialysis sessions. Ask the dialysis team when to measure and what the numbers mean for your parent.

Weight and fluid

Daily or regular weights show fluid. In advanced CKD or dialysis, weight between sessions reflects fluid gained, and the care team gives a "dry weight" and limits for gain. Use a reliable scale, weigh in the morning after passing urine, in similar clothing; see weighing scales and unplanned weight loss in older adults and daily weights in heart failure for technique that applies here too.

• A rapid gain over a few days, often a kilogram or more, with swelling or breathlessness, suggests fluid build-up and needs a call.
• A steady loss with poor appetite may signal undernutrition, which is common in advanced kidney disease.
• A rapid loss with dizziness, thirst and passing little urine may suggest dehydration.

Ask the doctor for your parent's personal thresholds.

Swelling and breathlessness

Look daily at the ankles, feet, legs, hands, eyelids and abdomen for swelling. Press a finger gently on the shin for a few seconds; a dent that stays suggests fluid. Note whether shoes and rings are tight. Watch for breathlessness on lying flat or on walking, and a new cough. These need a prompt call. If your parent has an oximeter, use it only as advised; see pulse oximeters.

Urine

Without any device you can notice:

• Amount: roughly how often and how much. A marked drop in urine, or none for many hours, with illness is a warning.
• Colour: pale straw is typical; very dark may mean dehydration; red, brown or cola colour or visible blood needs a doctor.
• Foam, smell, pain or burning may indicate infection or protein loss.
• Night-time urination changes.

People on dialysis may pass little urine already; the team will advise what is normal for them. If the doctor wants a urine measurement, they will give a measuring jug and instructions.

Blood sugar

If your parent has diabetes, which is a leading cause of CKD, follow the doctor's plan for testing and targets. Kidney disease changes how the body handles insulin and some diabetes tablets, raising the risk of low sugar, so know the signs and keep fast sugar at hand; see low blood sugar in older adults and how to test blood sugar at home step by step. Kidney disease and anaemia can also affect some test results, so tell the diabetes team.

Temperature and illness

Infections can quickly strain the kidneys, and older adults may not have a fever; see fever in older adults. Check temperature when unwell, note symptoms such as vomiting, diarrhoea or poor drinking and call early. Dehydration from vomiting and diarrhoea can cause sudden worsening of kidney function, and the doctor may temporarily adjust some medicines. Do not do this yourself.

Medicines and substances to be careful with

People with CKD are vulnerable to harm from some common medicines and products. Always ask the nephrologist or a pharmacist before giving:

• Painkillers of the anti-inflammatory type, which can damage the kidneys. Some people with CKD should avoid them completely.
• Herbal, Ayurvedic and traditional remedies, some of which contain heavy metals or substances harmful to the kidneys.
• Salt substitutes, which often contain potassium, dangerous in advanced CKD.
• Supplements, including potassium, magnesium and high-dose vitamins.
• Antacids and laxatives containing magnesium or aluminium.
• Contrast dyes used in scans; tell the radiology team about kidney disease.

Keep an up-to-date medicine list; see keeping a health record at home and polypharmacy and deprescribing. Never stop or change a medicine yourself.

Fluids, salt and diet

Advice varies widely: some people need to limit fluids, and others need to drink more. Salt and potassium limits depend on blood test results and stage of disease. A renal dietician can tailor advice to your family's meals. Do not follow general diet advice found online without checking with the care team. If fluids are restricted, use a marked jug to measure the daily allowance and spread sips through the day. Remember that foods like soups, fruit, dal and tea count towards fluid. Hidden salt in pickles, papad and packaged snacks is common.

Dialysis patients

If your parent is on dialysis, follow the dialysis unit's plan for weights, fluid limits and diet, and ask which readings and what thresholds they need. See living with dialysis: routines, travel and support. Protect the fistula arm: check daily for a thrill or buzz felt by placing fingertips over it; if it is absent, or if the arm becomes red, swollen, painful or bleeds, call the dialysis unit urgently. Do not carry heavy loads with that arm or wear tight clothing or jewellery on it.

Building a simple routine

• Daily: morning weight (if advised), look for swelling, note urine and appetite, take medicines as prescribed.
• Blood pressure: as the doctor advises, often a few days before each visit or a few times weekly.
• Blood sugar: as per the diabetes plan.
• Weekly: review the log and prepare questions.
• Before each visit: bring the log, medicine list and any recent lab reports.

Warning signs

Call the doctor the same day for:

• Weight gain with swelling or breathlessness.
• Much less urine, or very dark urine.
• Persistent vomiting, diarrhoea or poor drinking.
• Blood pressure much higher or lower than agreed.
• New itching, loss of appetite, nausea, taste change or marked tiredness.
• New confusion, muscle cramps or twitching.
• Signs of infection.

Call 112 for:

• Severe breathlessness, chest pain or fainting.
• Very slow or irregular pulse with weakness, which can occur with high potassium.
• Confusion, drowsiness or a seizure.
• Stroke signs.
• Very little or no urine with severe illness.

When to ask a professional

Ask the nephrologist or kidney nurse for personal targets for blood pressure, weight and fluids, what to do on sick days, which medicines to avoid and which arm to protect. Ask a renal dietician for a meal plan. Ask the pharmacist to check every new medicine. Seek help promptly for any warning sign above.