Hyperthyroidism

Hyperthyroidism is a condition where the thyroid gland produces more thyroid hormones than are needed by the body. It is also known as an overactive thyroid or thyrotoxicosis. 

•  Hyper - means ‘over –‘
  
  
• Hypo - means ‘under –‘

Content overview

Causes

Common symptoms

Diagnosis

Treatment options

Follow up

Further information

Causes

• Graves’ disease - the most common cause
  
  
• A toxic multinodular goitre (a goitre is an enlarged thyroid gland)
  
  
• A solitary toxic thyroid adenoma (an adenoma is a clump of cells)
  
  
• Thyroiditis (or inflammation of the thyroid gland) which is temporary 

Common symptoms

A speeding up of mental and physical processes of the whole body, such as:

• Weight loss, despite an increased appetite, although in a few cases patients may gain weight
  
  
• Palpitations / rapid pulse
  
  
• Sweating and heat intolerance
  
  
• Tiredness and weak muscles
  
  
• Nervousness, irritability and shakiness
  
  
• Mood swings or aggressive behaviour
  
  
• Looseness of the bowels
  
  
• Warm, moist hands
  
  
• Thirst
  
  
• Passing larger than usual amounts of urine
  
  
• Itchiness
  
  
• An enlarged thyroid gland
  
  

If the cause is Graves’ disease, you may also have thyroid eye disease, where the eyes may become prominent and feel gritty and sore. Smokers are up to eight times more likely to develop thyroid eye disease than non-smokers. 

Diagnosis

• By a physical examination and blood tests
  
  
• A low thyroid stimulating hormone (TSH) level with a high thyroxine (T4) level indicates hyperthyroidism 

Treatment options

• Antithyroid drugs
  
  
• Surgery to remove all or part of the thyroid gland
  
  
• Radioactive iodine to destroy most of the thyroid tissue 
  
  

Follow-up

Blood tests are carried out

• Every two to six months when you first start taking antithyroid drugs and every six to twelve months during long-term treatment with antithyroid drugs
  
  
• Frequently after radioactive iodine and surgery until stable, and once a year after that 
  
  

Further information

Read our guide to hyperthyroidism

Read our antithyroid drug alert card

Find information about treatments for hyperthyroidism

Living with thyroid conditions

Useful resources (films, patient stories, articles, events, phone support etc)

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