SymptomsOveractive thyroid (hyperthyroidism)
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:
- nervousness, anxiety and irritability
- hyperactivity – you may find it hard to stay still and feel full of nervous energy
- mood swings
- difficulty sleeping
- feeling tired all the time
- sensitivity to heat
- muscle weakness
- diarrhoea
- needing to pee more often than usual
- persistent thirst
- itchiness
- loss of interest in sex
Common signs
An overactive thyroid can also cause the following physical signs:
- a swelling in your neck caused by an enlarged thyroid gland (goitre)
- an irregular and/or unusually fast heart rate (palpitations)
- twitching or trembling
- warm skin and excessive sweating
- red palms of your hands
- loose nails
- a raised, itchy rash – known as hives (urticaria)
- patchy hair loss or thinning
- weight loss – often despite an increased appetite
- eye problems, such as redness, dryness or vision problems – read about the complications of an overactive thyroid for more about this
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.