Patient education
Electrolyte & Acid-Base Disorders
Electrolytes are minerals in your blood — sodium, potassium, calcium, magnesium, phosphate — that keep nerves firing, muscles contracting and the heart beating steadily. Your kidneys are the main organ keeping them in a very narrow, safe range.
The basics
What electrolytes do for you
Small changes in these levels can have large effects, because so many essential functions depend on them.
Sodium controls water balance and nerve signals
Potassium keeps the heart rhythm steady
Calcium supports bones, nerves and clotting
Magnesium enables hundreds of enzymes
Phosphate builds bone and stores energy
Bicarbonate keeps blood acidity in range
Why imbalances happen
Imbalance usually means intake, losses or kidney handling has shifted — often several at once.
Common problems
The imbalances seen most often
Low sodium
Hyponatraemia is the commonest imbalance. It causes tiredness, nausea, headache and confusion. It must be corrected slowly — raising sodium too fast is dangerous.
High potassium
Hyperkalaemia is common in kidney disease and with certain blood pressure medicines. It may cause no symptoms at all yet can trigger serious heart rhythm problems.
Calcium & phosphate
In kidney disease these drift together with parathyroid hormone and vitamin D, affecting bone strength and blood vessel health over years.
Recognising it
What imbalances feel like
Many people have no symptoms and the problem is found on a routine blood test. When symptoms do occur, they are often vague and easy to dismiss.
Symptoms are frequently non-specific. A simple blood test is the only reliable way to know your levels.
Possible symptoms
- Muscle cramps or weakness
- Tiredness and poor concentration
- Nausea or loss of appetite
- Palpitations or irregular heartbeat
- Numbness or tingling
- Confusion or drowsiness
- Seizures, in severe cases
Management
How imbalances are corrected
The approach depends on which electrolyte is affected, how severe it is, and how quickly it developed.
- 01
Find and treat the cause
Correcting the level alone is rarely enough. Vomiting, infection, uncontrolled diabetes or a medicine side effect all need addressing directly.
- 02
Review every medicine
Diuretics, ACE inhibitors, ARBs, potassium supplements, laxatives and some antibiotics all shift electrolytes. Dose changes often fix the problem.
- 03
Adjust diet where appropriate
Potassium or phosphate restriction is sometimes needed in kidney disease — but only when advised, since unnecessary restriction harms nutrition.
- 04
Correct fluid balance
Low sodium may need fluid restriction rather than more fluid. Dehydration needs careful replacement. Getting this right is the core of treatment.
- 05
Recheck and correct gradually
Levels are rechecked frequently during treatment. Rapid correction, especially of sodium, can cause serious harm — slow and steady is deliberate, not cautious.
- 06
Treat severe cases in hospital
Dangerous potassium levels, severe low sodium with confusion, or acid build-up need monitored inpatient treatment and occasionally dialysis.
Never take potassium, calcium or salt supplements on your own if you have kidney disease — they can be genuinely dangerous without monitoring.
When should you seek medical help?
Contact your doctor if you have
- Persistent muscle cramps or weakness
- Ongoing vomiting or diarrhoea
- Unusual drowsiness or confusion
- Palpitations
- A recent abnormal blood test result
Seek emergency care for
Severe muscle weakness, an irregular or very slow heartbeat, chest pain, seizures, or marked confusion and drowsiness.
The most important message
Electrolyte problems are common, usually correctable, and often silent. If you have kidney disease or take diuretics, periodic blood tests are simple insurance.
Bring your medicine list to every review.
If you are concerned about your kidney health, speak with a qualified healthcare professional. This information is for patient education and does not replace individual medical advice.