Treating underactive thyroid

An underactive thyroid (hypothyroidism) is usually treated by taking daily hormone replacement tablets called levothyroxine.

Levothyroxinereplaces the thyroxine hormone, which your thyroid doesn't make enough of.

You'll initially have regular Blood tests until the correct doseof levothyroxine is reached. Thiscan take a little while to get right.

You may start on a low dose of levothyroxine, which may be increased gradually, depending on how your body responds.Some people start to feel bettersoon after beginning treatment,while othersdon't notice an improvement in their symptoms for several months

Once you're taking the correct dose, you'll usually have a blood test once a year to monitor your hormone levels.

Ifblood tests suggest you may have an underactive thyroid, but you don't have any symptoms or they're very mild, you may not need any treatment. In these cases, your GP will usually monitor your hormone levels every few months and prescribe levothyroxine if you develop symptoms.

Taking levothyroxine

If you're prescribed levothyroxine, you should take one tablet at the same time every day.It's usually recommended that you take the tablets in the morning, although some people prefer to take them at night.

The effectiveness of thetablets can be altered by other medications, supplements or foods, so they should be swallowed with water on an empty stomach, and you should avoid eating for 30 minutes afterwards.

If you forget to take a dose, take it as soon as you remember, if this is within a few hours of your usual time. If you don't remember until later than this, skip the dose and take the next dose at the usual time, unlessadvised otherwise by your doctor.

An underactive thyroid is a lifelong condition, so you'll usually need to take levothyroxine for the rest of your life.

If you're prescribed levothyroxine because you have an underactive thyroid, you're entitled to a medical exemption certificate. This means you don't have to pay for your prescriptions.See getting help with prescription costs for more information on this.

Side effects

Levothyroxine doesn't usually have any side effects, because the tablets simply replace a missing hormone.

Side effects usually only occur if you're taking too much levothyroxine. This can cause problems includingsweating, chest pain , headaches , diarrhoea and vomiting.

Tell your doctor if you develop new symptoms while taking levothyroxine. You should also let them know if your symptoms get worse or don't improve.

Combination therapy

In the UK, combination therapy using levothyroxine and triiodothyronine (T3) together isn't routinely used because there's insufficient evidence to show its better than using levothyroxine alone (monotherapy).

In most cases,suppressing thyroid-stimulating hormone (TSH) using high dose thyroid replacement therapy should be avoided because it carries a risk of causing adverse side effects, such as atrial fibrillation (an irregular and abnormally fast heart rate), strokes , osteoporosis and fracture.

However, this type of treatment may sometimes be recommended in cases where a person has a history of thyroid cancer and theres a significant risk of it reoccurring.

Content supplied by the NHS Website

Medically Reviewed by a doctor on 29 Nov 2016