Kidney (Renal)


  • Ageing is a slow and normal process.  Not everyone experience aging at the same rate or the same method. Organs function starts to decline at a different rate, starting from the age of 30 years where the body cells start to reduce in numbers especially brain cells, liver and kidney.
  • In old age, the kidneys decline in size and function. Renal blood flow progressively decreases from 1200ml /minute between age 30 to 40 to 600mls /minute at the age of 80 due to decrease renal vasculature.

Symptoms and Signs

  • Older people have increased frequency or passing urine at night (nocturia) due to the inability of the aged kidney to concentrate urine and to handle extra water effectively.
  • Excessive or rapid fall in function is not part of normal aging process but due to complication of chronic illness like hypertension, diabetes mellitus or other diseases in earlier life.


Failing kidney has implications  such as:

  • Risk of adverse reactions from drugs or medications due to decreased drug clearance.
  • Risk of fluid volume overload (in heart failure: problem with excretion of water), dehydration (problem with retaining water), hyponatremia ( with thiazide diuretic: problem with concentrating urine), hypernatremia (associated with fever: problem with excretion of sodium salt), hyperkalemia ( with potassium –sparing diuretic: problem with excretion of potassium salt) and acidosis (problem with excretion of acid load).


  • Kidney function that is permanently lost is not reversible.
  • However, the rate of decline in function can be achieved by controlling diabetes mellitus and/or hypertension with lifestyle modifications and medications prescribe by doctor to prevent kidney complications from occurring.


  • Avoid medications (including traditional medications/herbs) that maybe toxic to the kidney (nephrotoxic). Choose only suitable medications at the correct dose (ask your doctor or pharmacist).
  • Prevent onset of diabetes and hypertension by regular medical check-up
  • Ask your doctors on assessment of fall risk if you have frequent nocturnal or urgent voiding.
Last Review : 28 August 2020
Writer : Dr. Sanidah binti Md. Ali
Reviewer : Dr. Ho Bee Kiau