Electrolyte Imbalance: What It Is, Why It Happens, and How to Fix It

Electrolytes may be small, but they play a big role in how the body runs. These charged minerals include sodium, potassium, magnesium, chloride, and calcium, and they keep nerves firing, muscles contracting, and fluids moving in and out of cells. If your levels fall out of balance, energy drops, performance suffers, and you'll be at risk of side effects ranging from annoying cramps to life-threatening. Fortunately, most everyday imbalances can be prevented with the right approach to hydration, fueling, and recovery. 

What’s an Electrolyte Imbalance? 

Electrolytes are charged minerals that regulate fluid balance, nerve signals, muscle movement, heart rhythm, pH, and blood pressure. An electrolyte imbalance happens when one or more of these minerals move outside the normal range and is often triggered by fluid shifts like dehydration or overhydration. 

Why Electrolytes Matter 

Sodium and potassium are key players in fluid balance and in keeping the heart and muscles working properly. Too little sodium can cause cells to swell, which is why hyponatremia can become serious quickly. On the flip side, too much potassium can trigger dangerous heart problems. These shifts help explain why electrolyte imbalance often shows up as fatigue, weakness, or fading energy during exercise. 

Common Causes and Risk Factors 

Electrolyte imbalance can happen for a few reasons. The most common ones include heavy sweating in hot weather, drinking too much plain water during long efforts, not drinking enough during training, gastrointestinal losses from vomiting or diarrhea, certain medications such as diuretics, and medical conditions that affect kidney or hormone function. The risk climbs during endurance events, illness, heat exposure, and with some drugs. 
 
There are also differences to watch for with dehydration in winter vs summer. In summer, you tend to lose more fluid from sweat which should be replaced during and after activity. Dehydration in cold weather happens because thirst cues can lag, and cold-induced diuresis increases urine output, so you can underdrink without realizing it. 

Symptoms to Watch For 

Low electrolyte symptoms differ based on which mineral is lacking and by how much. 

Mild Imbalances: 

Moderate Imbalances: 

Severe Imbalances: 

Hyponatremia (lack of sodium) commonly presents with nausea, headache, confusion, and can progress to seizures and coma. Hyperkalemia (lack of potassium) can lead to serious arrhythmias. Seek urgent care if you or someone else experiences severe symptoms. 

Diagnosis and Treatment Options 

An electrolytes blood test or electrolyte panel checks your mineral levels and helps pinpoint the issue. Clinicians may also order a basic or comprehensive metabolic panel and other labs based on your symptoms and history.  

How you fix an electrolyte imbalance depends on which electrolyte is out of range, whether it is high or low, and the cause. If you have a mild case, you can treat it at home by rehydrating with an electrolyte beverage, eating a salty meal, and resting. Usually the imbalance will resolve quickly. 

If your electrolyte imbalance is due to training, don't overdrink plain water, which will make things worse. In severe cases, med teams at endurance events will use small boluses of 3 percent saline based on established guidelines.  

For extreme hypo or hyper states, IV fluids, medications, or dialysis can be necessary, depending on the severity. 

Preventing electrolyte imbalances 

If you're wondering how to stay hydrated in hot weather, or how to stay hydrated in the winter, you can use this plan: 

Use thirst and the scale. For most gym sessions under an hour, drink to thirst. Weigh yourself before and after a hard session to gauge sweat losses. Aim to keep your body mass change within about 1 to 2 percent, and replace what you lost over the next few hours.