An overactive thyroid (hyperthyroidism) can cause a wide range of possible symptoms, although it's unlikely you'll experience all of them.

The symptoms may develop gradually or suddenly. For some people they're relatively mild, while for others they can be severe and significantly affect their life.

Common symptoms

Symptoms of an overactive thyroid can include:

Common signs

An overactive thyroid can also cause the following physical signs:

When to see your GP

See your GP if you have symptoms of an overactive thyroid. It might be useful to make a list of all your symptoms and show it to your GP.

These symptoms can have a number of causes. But a simple blood test can often help determine whether they're caused by a problem with your thyroid.

Read more about how an overactive thyroid is diagnosed.

Page last reviewed: 22/09/2016

Next review due: 22/09/2019