Electrolytes 101: what they do and when you need them

Electrolytes are minerals that carry a small electrical charge when dissolved in body fluids. The main ones are sodium, potassium, chloride, magnesium and calcium. They help control how much water is in and around your cells, and they are essential for nerve signals and muscle contractions, including your heartbeat.

For most people, everyday food and drink supply all the electrolytes they need. A varied diet with vegetables, fruit, dairy, nuts and pulses covers potassium, magnesium and calcium, while sodium usually comes easily from salt in food. Plain water is enough for most of daily life and for short, light exercise.

Sweat is where needs can change. When you sweat heavily, you lose water and also salt, mainly sodium. That can happen with long or intense exercise, outdoor work, or many hours in hot weather, which is a regular reality in a Saudi summer. In those situations, replacing both fluid and sodium can help, through salty food, an oral rehydration solution or a sports drink.

Signs you may be losing a lot through sweat include visible salt marks on skin or clothes, heavy dripping sweat, muscle cramps and unusual tiredness in the heat. These signs are not specific, so on their own they do not prove an electrolyte problem.

More is not always better. Drinking large amounts of plain water over many hours without any salt can dilute the sodium in your blood, a rare but serious problem seen mostly in endurance events. Taking salt or electrolyte supplements when you do not need them adds sodium you may already get plenty of.

Speak to a doctor or pharmacist before using electrolyte products if you have kidney disease, heart disease or high blood pressure, or take diuretics or similar medicines, because your sodium and potassium may need careful control. Seek medical care promptly for severe vomiting or diarrhoea, confusion, or symptoms of heat exhaustion.