If you have a thyroid problem that is not treated properly, serious health problems can result.
An overactive thyroid (hyperthyroid) can lead to a number of problems such as:
- eye problems, such as bulging eyes, blurred or double vision or even vision loss
- heart problems, such as rapid heart rate, problems with heart rhythm or heart failure - these problems can usually be treated
- brittle bones (osteoporosis)
- red, swollen skin - occurring particularly on the shins and feet
- thyrotoxic crisis, which is a worsening of symptoms causing fever, rapid heart rate and delirium - this requires urgent medical attention.
An underactive thyroid (hypothyroid) can cause a range of complications, including:
- an enlarged thyroid, or goitre, which may cause problems with swallowing and breathing
- high cholesterol and associated heart disease
- nerve damage causing tingling, numbness and pain in the arms, legs or other affected areas
- birth defects
- miscarriage or premature birth
- mental health issues such as depression
- myxedema, which is a rare, life-threatening condition involving intense cold intolerance, lethargy and drowsiness that can lead to unconsciousness - myxedema requires urgent medical attention.
Last reviewed: November 2016