Potassium and blood pressure medication: what should you know?

Potassium helps nerves and muscles work, including the heart. Some medicines used for Hypertension can raise potassium, while others can lower it through changes in how the kidneys handle salt and water. Kidney disease, dehydration, supplements and potassium-containing salt substitutes can alter the balance. Symptoms may be vague, and an abnormal level may sometimes cause muscle weakness, tingling or an unusual heartbeat, so a blood test is more reliable than symptoms alone.

Take your medicine as prescribed and do not start potassium tablets, electrolyte products or a salt substitute without checking first. Give your clinician a complete list of medicines, vitamins and herbal products. Keep blood-test appointments so potassium and kidney function can be reviewed after treatment changes. Do not deliberately avoid all potassium-rich foods unless advised; dietary changes depend on your result and overall health.

Seek urgent help for severe weakness, fainting, chest discomfort, difficulty breathing or a new irregular heartbeat. Contact your prescriber promptly if you develop persistent muscle cramps, marked tingling, vomiting or diarrhoea while taking treatment, because fluid and mineral changes may need assessment.

Ask whether your medicine tends to raise or lower potassium, when your next blood test is due, and whether any supplement or salt substitute is suitable. Ask what to do if illness prevents normal eating or drinking.