Potassium is a mineral that's important for the working of your heart, kidneys, liver, muscles and nerves. Getting enough potassium can also help lower your risk of heart disease and stroke. The amount of potassium you need depends on your age, sex and any medical conditions you may have. You should be able to get all the potassium you need by eating a varied and balanced diet.
Our kidneys help to control the level of potassium in the blood. Potassium not needed by the body is usually passed out in the urine. Low or high potassium is more common in older people and those with other conditions such as kidney problems or heart failure.
Too much potassium
People with kidney problems often have high potassium levels as the kidney is unable to remove potassium from the body. Some medicines can cause your body to hold on to potassium, eg, ACE inhibitors, spironolactone or angiotensin receptor blockers. Too much potassium can cause stomach pain, feeling sick and diarrhoea (runny poo). A high level of potassium can be dangerous, as it can affect your muscles and heart.
Too little potassium
Some conditions may lower your potassium levels, such as ongoing diarrhoea and vomiting, inflammatory bowel disease and medications such as diuretics (water pills), corticosteroids or excessive use of laxatives. Too little potassium can make you feel tired or nauseous (sick). If your potassium levels are low for a long time, this can cause high blood pressure, breathing problems or can cause your heart to beat irregularly.