An underactive thyroid is usually treated with medicine to replace the thyroid hormone that your body cannot produce. This medicine is usually levothyroxine tablets.

You'll usually need to take them for the rest of your life to prevent your symptoms returning. You should be able to live a normal life.

You'll have regular blood tests to check you're on the right dose of levothyroxine. Being on the wrong dose can cause side effects, such as feeling or being sick, diarrhoea, headaches or problems sleeping. If you have any side effects, talk to your GP or a pharmacist.