Potassium, sodium and cortisol: what electrolytes can show about the adrenal glands

Sodium and potassium are electrolytes, minerals in your blood that help control fluid, blood pressure, muscles, nerves and the heartbeat. They show up on routine blood panels, and some adrenal disorders push them out of range. One link between the adrenal glands and these minerals is aldosterone, a second adrenal hormone that helps balance sodium and potassium, according to MedlinePlus.

An electrolyte result can hint at an adrenal problem. It can’t diagnose one, and most abnormal electrolytes have other causes.

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A basic metabolic panel checks electrolytes, glucose and kidney markers. It does not test cortisol or diagnose an adrenal condition. The seller's page says to fast for at least 8 hours.

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Which blood panels include electrolytes

MedlinePlus describes three groups of tests that include them:

• Electrolyte panel. Sodium, chloride, potassium, bicarbonate, calcium, magnesium and phosphate.
• Basic metabolic panel (BMP). Eight substances: glucose, calcium, sodium, potassium, carbon dioxide, chloride, BUN and creatinine.
• Comprehensive metabolic panel (CMP). The same eight plus six more: albumin, total protein and four liver tests (ALP, ALT, AST and bilirubin).

Neither the BMP nor the CMP measures cortisol. They are general-health panels, and MedlinePlus lists fatigue among the reasons to order a CMP. See routine blood work and cortisol.

Low sodium and cortisol

MedlinePlus says low sodium (hyponatremia) can be a sign of:

• Loss of sodium through diarrhea or vomiting.
• Conditions that make the body hold extra fluid, such as kidney disease, cirrhosis and heart failure.
• Some medicines, including many over-the-counter pain relievers and some antidepressants.
• Addison disease.
• Malnutrition.

Symptoms can include weakness, fatigue, confusion and muscle twitching. Without treatment, extremely low sodium can cause seizures and coma.

High and low potassium

MedlinePlus lists these causes of high potassium (hyperkalemia): kidney disease, Addison disease, injuries, burns or surgery, poorly controlled type 1 diabetes, and some medicines. Symptoms include fatigue, muscle weakness, nausea, numbness or tingling, and an irregular heartbeat.

For low potassium (hypokalemia), it lists diuretics, fluid loss from diarrhea, vomiting or heavy sweating, too many laxatives, kidney disease, alcohol use disorder, and adrenal gland disorders including Cushing syndrome and aldosteronism. Symptoms include muscle cramps, weak or twitching muscles, fatigue, nausea and an irregular heartbeat.

So if you are searching for “low potassium adrenal” or “adrenal gland low potassium,” the adrenal causes on MedlinePlus’s list are Cushing syndrome and aldosteronism. They are far from the only causes.

Adrenal conditions and electrolyte patterns

Condition	What MedlinePlus lists
Addison disease (low cortisol and aldosterone)	Lower sodium, higher potassium
Cushing syndrome (too much cortisol)	Lower potassium
Primary aldosteronism (too much aldosterone)	Lower potassium. High blood pressure with low potassium is a reason to test aldosterone

MedlinePlus says aldosterone keeps blood pressure stable by balancing sodium and potassium. It describes primary aldosteronism as usually caused by a benign tumor on an adrenal gland, and says doctors may test aldosterone when high blood pressure comes with low potassium. See aldosterone-renin ratio for that work-up.

What electrolytes looked like in adrenal insufficiency

A small hospital series of 60 people with primary adrenal insufficiency from Warsaw gives numbers (Int J Endocrinol, 2013):

• Sodium was low in everyone hospitalized for adrenal crisis or imminent crisis. In people without a crisis it was low or at the lower end of normal.
• Low sodium appeared at least three months before the diagnosis in 34 people (57 percent) and wasn’t followed by the right diagnosis at the time.
• High potassium was found in 11 people (85 percent) with a full crisis and 7 people (54 percent) with an imminent crisis. It wasn’t found in anyone without a crisis.

The authors conclude that doctors need more training on signs, symptoms and electrolyte changes that are most typical of the disease. Two things follow for you. Low sodium that no one explains is worth raising with a clinician. And normal potassium doesn’t rule adrenal insufficiency out, because none of the people without a crisis in that series had high potassium. This is one single-center series, so treat the percentages as illustrative.

What a result can’t tell you

• The cause. MedlinePlus says sodium results are looked at together with other tests, and that an abnormal result doesn’t always mean a condition that needs treatment. Medicines, age, sex and other conditions can change sodium, and some medicines and supplements can change potassium.
• Whether you have an adrenal problem. NIDDK says doctors confirm adrenal insufficiency with cortisol tests, most often the ACTH stimulation test, and then look for the cause. Electrolytes support that work. They don’t replace it. See low cortisol testing.

Safety

Don’t wait for a test if you have:

• Vomiting you can’t stop, together with severe weakness.
• Fainting, confusion or seizures.
• Muscle weakness with a fast or irregular heartbeat.

Call 911 or go to an emergency room. See adrenal crisis. If you take a diuretic, a steroid or any other medicine, don’t change it because of an electrolyte result. Ask your prescriber.

Ordering electrolytes yourself

The seller’s page for the BMP and CMP says to fast for at least 8 hours beforehand, with only water allowed. MedlinePlus says you may need to fast for the BMP and CMP, and that a stand-alone electrolyte panel needs no special preparation. Follow the instructions on your lab order.

The CMP includes everything in the BMP plus liver and protein markers. If your question is only about sodium and potassium, the BMP covers them.

• CMPThe basic panel plus liver and protein markers $39 See this test at HealthLabs

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Take the result to a clinician. A high or low sodium or potassium can matter on its own, whatever the cause.

Questions people ask

Does cortisol affect sodium?

MedlinePlus lists Addison disease, where cortisol is low, among the causes of low sodium. Beyond that, the sources used here don’t describe the mechanism.

Can low potassium come from adrenal problems?

Yes, MedlinePlus lists Cushing syndrome and aldosteronism, both adrenal disorders. It lists several other causes first, including diuretics, vomiting, diarrhea and kidney disease.

Can I have an adrenal problem with normal electrolytes?

Yes. In the Warsaw series, potassium was not high in anyone without a crisis, and sodium was only low or low-normal. Electrolytes are a clue, not a verdict.

Keep reading

• Aldosterone-renin ratio

  The test for aldosterone, blood pressure and potassium.

• Low cortisol

  Causes, emergency signs and how it is tested.

• Adrenal crisis

  Warning signs and what to do.

• All adrenal and related tests

  ACTH, DHEA-S, aldosterone and more.