How to test electrolyte status (and tips to correct deficiencies)

Testing electrolyte status can be confusing. Why? While blood tests are commonly used to assess electrolyte status, they don’t actually reflect total body hydration or mineral sufficiency. Blood levels are tightly regulated by your body, meaning it will pull electrolytes from tissues like bone or muscle to keep blood levels within a normal range — even if the rest of the body is depleted. So, “normal” blood electrolyte levels can be misleading; they don’t necessarily indicate optimal hydration or electrolyte balance at the cellular level, and can’t always identify moderate nutrient deficiencies.

On the other hand, if blood electrolyte results are out of range, it’s typically an indicator of a larger issue and can’t necessarily be remedied by diet alone.

In this article, I’ll help clear up confusion about electrolyte panels, and share tips to assess your electrolyte status properly with your doctor. But the main takeaway if you read no further is that normal blood electrolyte levels don’t always mean you’re consuming enough electrolytes, and other important data points to consider are:

1. Symptoms. Electrolyte deficiencies can often present as tiredness, headaches, muscle cramps, and brain fog.
2. Diet. Healthy diets are typically low in sodium in particular, and you may not be getting enough through diet alone.

I’ll start by talking through what defines an electrolyte deficiency, then speak to assessing your sodium, potassium, magnesium, and calcium, and wrap up with four tips to improve your electrolyte intake.

Electrolyte Imbalance vs. Electrolyte Deficiency

Let’s begin getting clear about electrolyte imbalances versus electrolyte deficiencies, because they’re not the same.

An electrolyte imbalance is when blood levels of an electrolyte are too low or too high (again, likely an indicator of something else going on, like an illness). An electrolyte deficiency is an inadequate dietary intake of an electrolyte, and may or may not affect how you feel on the daily.

Electrolyte imbalances

The primary causes of electrolyte imbalance include:

• Kidney or heart failure
• Vomiting or diarrhea from illness (can cause potassium imbalance)
• Diuretic medications
• Consuming excess alcohol
• Overhydration with plain water (may cause sodium imbalance)

Why doesn’t an inadequate consumption of electrolytes cause an imbalance? That’s because your body works hard to prevent low blood electrolyte levels, even when dietary intakes are low or high. Maintaining normal blood electrolyte levels allows for crucial functions like cellular communication and fluid balance.

For one example of how your body maintains blood electrolyte levels, we can look at the kidneys. If sodium or potassium levels get too high, your kidneys excrete more electrolytes through urine. When they’re too low, it slows down excretion, keeping more of these electrolytes in your body.

It’s not just the kidneys, though. Your body has another way of maintaining serum electrolytes when they fall too low: tapping into the human skeleton.

Yes, your body breaks down bone (yikes!) to keep minerals like sodium, calcium, and magnesium within normal ranges in your blood. That’s how important these elements are to normal physiologic function.

What about electrolyte deficiency?

While electrolyte deficiency won’t show up on a blood test, you may still feel it in your energy levels or elsewhere.

The symptoms of electrolyte deficiency are often subtle. Depending on the electrolyte, folks may have low energy, muscle cramps, headaches, poor sleep, irritability, brain fog, dizziness, or weakness.

Of course, many other conditions can also drive these signs and symptoms. It’s important to address any electrolyte deficiencies in conjunction with other aspects of health — sunlight, movement, eating healthy foods, and addressing underlying conditions (just to name a few) can all significantly impact our health, too, and electrolytes are often just one piece of a larger puzzle.

Testing Electrolyte Status

Let’s talk about how to address sodium, potassium, magnesium, and calcium status holistically.

Assessing Sodium Status

A normal sodium blood test doesn’t indicate you’re getting enough sodium. I’ve hammered that point already.

So, how do you know if you need more sodium? Look at these areas:

• Symptoms. Monitor how you feel. Sodium deficiency often presents as tiredness, headaches, muscle cramps, brain fog, and carb cravings. You’ll feel the difference when you get your sodium intake right.
• Diet. Whole food diets are naturally low in sodium, plus low-carb and keto diets increase urinary sodium loss.
• Sweat loss. Sodium is the primary electrolyte lost in sweat, and the more you sweat, the more sodium you’ll need. Athletes exercising in the heat can lose up to 7 grams of sodium per day.

To go deeper, read our article on factors that increase electrolyte needs. You can also check out our Sodium Intake Calculator for an estimation of how much sodium you may need on a daily basis.

Assessing Potassium Status

Potassium deficiency can be a little harder to nail down, and only about 25% of American adults hit the National Academy of Medicine (NAM) adequate intake of 3.4 g/day for men and 2.6 g/day for women (and optimal intakes may be higher, in the range of 3.5–5 grams per day).

Here are areas to consider when assessing if you’re consuming enough potassium.

• Blood pressure. Research links potassium deficiency with elevated blood pressure, a heart disease risk factor — though to be clear, low dietary potassium is only one possible contributor to high blood pressure, and blood pressure is affected by a wide variety of diet and lifestyle choices.
• Potassium deficiency symptoms, including muscle cramps, constipation, tiredness, constipation, malaise, and weakness. Though in general, potassium symptoms might not be as obvious as sodium deficiency symptoms, so you won’t want to fully rely on these.
• Consider what potassium-rich foods you’re eating, or can add in.

You can watch these symptoms and your diet to calibrate your potassium intake.

Assessing Magnesium Status

As with potassium and sodium, you can’t rely on blood testing to know if you’re getting enough magnesium. Only 0.3% of total body magnesium is present in the blood, so it’s hard to get an accurate reading there.

Signs of magnesium deficiency may include:

• Muscle cramps
• Fatigue or weakness
• High blood pressure (hypertension)
• Increased inflammation
• Kidney stones
• Osteoporosis (brittle bones)
• Cardiac arrhythmias
• Heart palpitations

Again, though, these symptoms can stem from many other causes. So, a smart strategy is to watch for these symptoms while eating magnesium-rich foods. Our ancestors ate about 600 mg of magnesium daily, and you’ll unlikely to overshoot this mark with a magnesium-rich diet. 

Assessing Calcium Status

If you’re low on dietary calcium, your body will pull it from bone to maintain blood serum levels — keeping blood levels stable even though you may not be consuming enough for the rest of your body.

Most adults can benefit from around 1 gram of daily calcium to support bone health, muscle health, and other vital functions. Diet is the best place to consume calcium, since some evidence suggests calcium supplements may increase heart disease risk. Calcium-rich foods include dairy, leafy greens, and tofu.

4 Tips for Improving Electrolyte Status

Here are three tips to help you make sure you’re consuming enough electrolytes.

#1: Use the salt shaker liberally

Most people need more salt. Active folks lose extra sodium through sweat, low-carb folks lose extra sodium through urine, and many folks are afraid of the salt shaker.

Check out our sodium calculator for more guidance on getting enough salt. You might be surprised at how much you actually need — and the salt shaker is an easy way to start increasing your daily intake.

#2: Eat electrolyte-rich foods

The salt shaker is a start, but the foods you’re salting and eating matter, too — especially when it comes to the electrolytes you can’t get through the salt shaker. Here are foods to focus on for each electrolyte:

• Sodium: salt, pickles, and cured meats/cheeses.
• Potassium: dark leafy greens, meat, potatoes, and fruit.
• Magnesium: dark leafy greens, chocolate, and nuts.
• Calcium: dairy, soybeans, and cruciferous vegetables.

To learn more, check out this guide to electrolyte-rich foods.

#3: Drink electrolytes

Have you befriended the salt shaker and stocked your diet with electrolyte-rich foods, but still aren’t getting enough electrolytes? Electrolyte drinks can help fill in any gaps. We formulated LMNT to complement folks’ electrolyte intake from their diets, and you can also make electrolyte drinks at home.

#4: Listen to how you feel

Our bodies need electrolytes to function — and when you get the right amount, you can feel the difference. For some folks, it may look like improved energy and fewer cravings; for others, they may experience better performance in the gym or recovery after. Tinker with the salt shaker, your foods, and electrolyte drinks, and listen to your body — you’ll see the signals when you find the intake that’s right for you.