Potassium [K]

Potassium comes from diet - especially fruit, vegetables, nuts. Its levels in blood are often high in people with kidney diseases, and in those treated with some drugs. This is important as it can be dangerous. Normal = 3.5-5.0 mmol/litre.

Result
Comments
below 3.5
Too low. If below 3.0, may feel weak, and in susceptible people heart rhythm may be upset.
3.5-5.0
Normal
5.0-6.0
High but usually not dangerous - getting closer to dangerous at 6.0.
6.5+
Dangerously high

Some diseases and drugs can change potassium levels. ACE inhibitors and ARBs (drugs ending -ipril, and -sartan) as well as spironolactone and some other drugs can raise potassium levels.

Kidney disease may cause high potassiums, especially in combination with drugs that can do the same. The problem is worst in those with very little kidney function, in particular in patients on haemodialysis. Low potassium is common after haemodialysis, when it is usually temporary. If below 3.0, may feel weak, and in susceptible people heart rhythm may be upset. It is common to arrive for haemodialysis with a slightly high potassium level.

More info about potassium from Lab Tests Online


This page created 6th December 2004, last modified July 7, 2015, on the PatientView website