PATIENT INFORMATION
Why do I need kidney tests or electrolytes?
Kidney function and electrolyte results can matter because the kidneys affect fluid balance and the handling of many medicines.
What these tests usually include
- Creatinine and eGFR, which estimate how well the kidneys are working
- Sodium and potassium, which affect nerves, muscles and heart rhythm
When they may be requested
Testing may be relevant in people with kidney disease, diabetes, cardiovascular disease, certain medicines, dehydration or surgery where significant fluid shifts are expected. Medicines that can affect these results include water tablets, some blood-pressure medicines and some diabetes medicines.
Electrolytes are not necessarily needed routinely in every healthy patient. A targeted test is more useful when the result could change treatment or anaesthetic management.
Why the results help
They can guide which medicines and doses are safe, how fluids are given, and whether any imbalance needs correcting before surgery. They also give a starting point to compare with after surgery.
An abnormal result needs interpretation in your clinical context. Do not decide whether surgery is safe, or change treatment, solely from information on this website.