What You Need to Know About Hyperthyroidism
What hyperthyroidism means
Hyperthyroidism occurs when the thyroid gland produces too much thyroid hormone. Because the thyroid regulates metabolism, heart function, energy, temperature, and many body processes, excess hormone speeds the body up. Symptoms can develop gradually or more quickly, and they are often mistaken for stress, anxiety, or lifestyle pressure, so understanding early signs helps you seek timely care.
Common symptoms of hyperthyroidism
People experience hyperthyroidism differently, but symptoms often include:
unexplained weight loss despite normal or increased appetite
heat intolerance, sweating, and feeling uncomfortably warm
palpitations, fast heart rate, or racing heartbeat
anxiety, irritability, tremor, or restlessness
poor sleep
frequent bowel motions or diarrhoea
muscle weakness or tiredness
menstrual cycle changes
Some thyroid conditions also cause a visible neck swelling (goitre). Certain autoimmune thyroid conditions may cause eye symptoms such as irritation, redness, bulging, dryness, or visual changes.
Red flags — seek urgent review if these occur
severe or persistent palpitations
fainting, dizziness, chest pain, or breathlessness
sudden, painful, or rapidly enlarging neck swelling
severe or sudden eye pain or rapid vision change
fever with severe neck tenderness
These may indicate more serious complications that require urgent assessment.
What causes hyperthyroidism
Common causes include autoimmune conditions such as Graves’ disease, thyroid nodules producing excess hormone, inflammation of the thyroid, and medication or iodine-related causes. Risk varies between individuals, and causes are confirmed with medical assessment rather than assumption.
How hyperthyroidism is diagnosed
Diagnosis involves blood tests to measure thyroid hormone levels and thyroid stimulating hormone (TSH). Depending on results, your doctor may arrange further blood tests, ultrasound, or specialist review. Identifying the underlying cause helps guide safe, appropriate treatment.
Treatment and outlook
Treatment is tailored to the cause and your health situation. Options may include medication to reduce hormone levels, treatment to calm heart rate, or specialist therapies if needed. Many people do well with treatment and ongoing monitoring. Recovery may be gradual, and regular follow-up supports safe care and long-term wellbeing.
When to see your GP
See your GP if you experience persistent palpitations, heat intolerance, unexplained weight loss, anxiety symptoms, or new neck swelling. Early assessment leads to clearer answers, safer management, and reassurance where appropriate.
This article provides general health information only and does not replace medical advice. Please speak with your GP for personalised care.