Optimal - The Blog

April 30, 2019

Know Your Biomarkers: Sodium and Potassium

Welcome to another episode of KNOW YOUR BIOMARKERS! In today’s video, Dr. Weatherby will be talking about Sodium and Potassium. We see both of these on almost every chemistry screen but they are often overlooked as not being that helpful. Nothing could be further from the truth! My goal with these videos is to be a summary of the biomarkers that appear in the ODX Application and provide the info you need to know to evaluate biomarkers and understand the high and low values.

So, back to Sodium and Potassium. They are both electrolytes and are both measured in the blood and results appear on a standard Blood chem screen.

Let’s start things off by looking at Sodium. Constituting 90% of the electrolyte fluid, sodium is the most prevalent cation in the extra-cellular fluid. Sodium acts as the chief base of the blood where it aids in maintaining acid-base balance. It also functions to maintain osmotic pressure, aids in nerve impulse transmission, and is essential for cellular transport as part of the sodium-potassium pump.

Potassium, on the other hand, is the main intracellular cation and acts as the primary intracellular pH buffer. The majority of potassium (90%) is found inside the cell, with only small amounts found in other tissues, such as bone and blood. Potassium, along with sodium, plays an important role in the kidney’s regulation of pH.

With elevated Sodium and Potassium suspect Dehydration. Dehydration is a very common problem and should be factored into your blood chemistry and CBC analysis. Dehydration causes hemoconcentration of the blood sample and as such, along with increased sodium and potassium levels, you can expect to see a relative increase in the Red Blood cell Count as well as an increase in hemoglobin and hematocrit values.

Interestingly enough, increased potassium is also a sign of tissue damage and cellular rupture. Remember, the majority of the potassium is inside the cell so any trauma to tissue and cells will cause potassium to leach out. Something to pay attention to!

Both sodium and potassium are under the influence of adrenal cortex hormones, especially the mineralocorticoid aldosterone, which is synthesized in the Zona Glomerulosa region of the adrenal cortex.

Aldosterone has a somewhat stronger effect on sodium where it causes the body to hold onto sodium by decreasing excretion of sodium through the kidneys into the urine.

On the other hand, Aldosterone causes the kidneys to increase the excretion of potassium, so these 2 electrolytes have opposing regulatory actions.

Low aldosterone, as seen with adrenal insufficiency, causes an increase in the amount of sodium excreted by the kidneys into the urine and thus leading to a decreased serum sodium.

It has the opposite effect on potassium. Low aldosterone causes the kidneys to hold onto potassium and reduces potassium in the urine thus leading to increased serum potassium.

Addison’s disease, a disease of low adrenal hormone output is so dangerous because of the sodium wasting that happens.

As such, sodium and potassium levels can be a marker for adrenal dysfunction.

To round this one out, Increased serum sodium levels and decreased potassium levels are associated with adrenal stress (increased adrenal hormones reduce the amount of sodium that gets excreted into the urine thus raising serum levels AND increases the amount of potassium excreted in the urine thus causing low serum potassium.

One of the great ratios we calculate and report on in the Optimal DX application is the sodium: potassium ratio. It’s very helpful for assessing chronic stress, inflammation, and adrenal insufficiency as well as an indicator of catabolism. I’ll be sure to cover this important ratio in detail in a future session!

Lastly, I want to talk about one final thing and that is using the serum levels of sodium and potassium, along with other electrolytes to gauge the Electrolyte Status in our patients.

Electrolyte Status:

A relative electrolyte status can be determined by looking at levels of sodium, magnesium, calcium, and potassium, along with phosphorous and chloride.

An electrolyte imbalance can affect the body’s acid-base system, hydration, and even the movement of ions across the cell membrane. An electrolyte imbalance can show up as low blood pressure, cold hands or feet, poor circulation, swelling in the ankles, and immune insufficiency.

We can look at the relative decrease in these biomarkers to determine a patient’s Electrolyte Status, which we calculate in the Optimal DX application and report on the Functional Health Report:


A high Electrolyte Status score indicates that there’s a degree of imbalance in the body’s electrolytes: potassium, sodium, chloride, phosphorous, calcium, and magnesium. You can then examine the individual nutrient values to identify which electrolytes might be deficient.

So that’s it for our brief summary of Sodium and Potassium. I hope this has been helpful and I look forward to seeing you on another of our “Know Your ODX Biomarkers” videos in the very near future.

This has been Dr. Weatherby from Optimal DX. Take care.

Tag(s): Biomarkers

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