What Are Electrolytes? What They Do and When You Need More

Author: Sam Akintola · Posted: October 23, 2026 · Updated: October 23, 2026

#electrolytes #potassium #hydration #minerals

The short answerElectrolytes are minerals that carry an electric charge when dissolved in body fluids, including sodium, potassium, chloride, calcium, magnesium, phosphate and bicarbonate. They help balance fluids, send nerve signals and make muscles contract, including your heart. Most people get enough from food and water, but heavy sweating, vomiting or diarrhea can raise needs.

A baked potato split open, a bunch of bananas, a bowl of plain yogurt, a dish of dried apricots and a glass of water on a bright kitchen counter

Electrolytes are minerals that carry an electric charge when they’re dissolved in your body’s fluids. The main ones are sodium, potassium, chloride, calcium, magnesium, phosphate and bicarbonate. They help balance the water inside and outside your cells, carry nerve signals, make muscles contract, including your heartbeat, and keep your blood’s acidity in a healthy range. Most people get enough from everyday food and drink, but heavy sweating, vomiting or diarrhea can throw them off.

The main electrolytes and what they do

Electrolyte	Key jobs	Good food sources
Sodium	Fluid balance, nerve signals, muscle contraction	Table salt and most packaged foods; small amounts in many whole foods
Potassium	Fluid balance, heart rhythm, muscle function, blood pressure	Potatoes, beans, lentils, bananas, dried apricots, yogurt, leafy greens
Chloride	Fluid balance, stomach acid	Table salt, seaweed, tomatoes, olives
Calcium	Muscle contraction, nerve signals, bones and teeth	Dairy, fortified plant milks, calcium-set tofu, leafy greens, canned fish with bones
Magnesium	Muscle and nerve function, energy production, heart rhythm	Nuts, seeds, beans, whole grains, leafy greens
Phosphate	Bones, energy storage, cell membranes	Dairy, meat, fish, beans, nuts, whole grains
Bicarbonate	Keeps blood pH balanced	Made by the body, so you don’t need to eat it

How your body keeps the balance

Your kidneys are the main managers. They filter your blood and decide how much of each electrolyte to keep or release in urine, guided by hormones and by how much water you drink. Thirst nudges you to drink when fluids run low. In healthy people, this system works remarkably well without any special effort.

Potassium: the one many people miss

Most Americans get plenty of sodium but not enough potassium, which is why the Dietary Guidelines for Americans, 2020-2025, list potassium as a dietary component of public health concern. The National Academies set an Adequate Intake of 3,400 milligrams a day for adult men and 2,600 milligrams for adult women.

Food	Portion	Approximate potassium
Dried apricots	1/2 cup	about 750 mg
Lentils, cooked	1 cup	about 730 mg
Potato, baked, flesh only	1 medium	about 610 mg
Kidney beans, canned	1 cup	about 600 mg
Banana	1 medium	about 420 mg
Milk, 1%	1 cup	about 370 mg
Spinach, raw	2 cups	about 330 mg
Salmon, cooked	3 oz	about 330 mg

Eating more potassium-rich food is one of the most practical ways to support healthy blood pressure, a key idea behind the DASH diet. Pairing it with less sodium helps even more, as our guide to sodium explains.

When you might need more

Long or intense exercise, especially in heat, when you sweat heavily. Sweat contains mostly sodium, with smaller amounts of potassium and other minerals.
Hot weather or hours of outdoor physical work.
Vomiting or diarrhea, which can drain fluids and electrolytes quickly. Oral rehydration solutions, long promoted by the World Health Organization for dehydration caused by diarrhea, contain a balanced mix of salts and sugar.
Very low-carbohydrate diets, which can increase sodium and water losses in the first days; see our guide to the keto diet.

Do you need electrolyte drinks?

For most of daily life, including a typical workout of under about an hour, water and regular meals provide all the electrolytes you need. Sports drinks can help during long or intense sessions with heavy sweating, but many contain added sugar, and some electrolyte powders pack large amounts of sodium. If you’re simply thirsty, water is usually the best choice; our guide on how much water to drink has more.

Talk with your doctor before using electrolyte supplements if you have kidney disease, heart failure or high blood pressure, or take medications that affect potassium or sodium, such as certain diuretics or blood pressure drugs.

Signs of an imbalance

Mild imbalances may cause muscle cramps, weakness, fatigue, headache or nausea. More serious ones can lead to confusion, an irregular heartbeat or seizures. Seek medical care promptly for severe symptoms, especially after prolonged vomiting or diarrhea, or if a young child or older adult in your care seems dehydrated.

The bottom line

Electrolytes are charged minerals, like sodium, potassium, calcium and magnesium, that keep your fluids balanced and your nerves, muscles and heart working. Most people get enough from a varied diet and water, though potassium often runs low. Extra electrolytes can help after heavy sweating or illness, but everyday hydration rarely calls for more than water and good food.

Frequently asked questions

Do I need electrolyte drinks every day?

Most people don't. Regular meals and water supply plenty of electrolytes for daily life and typical workouts. Electrolyte drinks are mainly useful during long or intense exercise with heavy sweating, in extreme heat, or when recovering from vomiting or diarrhea.

What foods are high in electrolytes?

Potatoes, beans, lentils, bananas, dried apricots, yogurt and leafy greens are rich in potassium. Nuts, seeds and whole grains provide magnesium, and dairy and fortified plant milks supply calcium. Sodium and chloride come mainly from salt.

Are sports drinks good for hydration?

They can help during long, intense or hot sessions when you lose a lot of sweat, because they replace some sodium and provide quick carbohydrate. For everyday hydration they aren't needed, and many contain added sugar, so water is usually the better choice.

What are the signs of low electrolytes?

Mild imbalances can cause muscle cramps, weakness, fatigue, headache or nausea. Severe ones can lead to confusion, irregular heartbeat or seizures, which need urgent medical care. Imbalances are more likely after prolonged vomiting or diarrhea or with certain medications.

Sources

This guide is general information, not medical advice. For a health condition, pregnancy or a history of disordered eating, please talk with a doctor or registered dietitian.