What should you know about subacute hyperthyroidism?

The thyroid may become painful and tender, sometimes after a recent infection. Inflamed thyroid cells can release hormone already stored in the gland, producing an overactive pattern even when the gland is not making new hormone faster. Symptoms can include a racing or pounding heartbeat, feeling hot, sweating, nervousness, poor sleep, loose stools, and tiredness. Neck pain may spread towards the jaw or ear. The overactive phase can later be followed by a period when the thyroid is underactive, so follow-up blood tests matter. Read more about Hyperthyroidism for the broader condition.

Arrange a clinical assessment for neck pain with palpitations or other new overactive-thyroid symptoms. Testing commonly includes thyroid blood tests and may include checks for inflammation; the pattern helps distinguish thyroiditis from other causes. Rest, drink enough fluid, and limit triggers that make palpitations or shakiness worse, such as excess caffeine. Take only medicines recommended for you, because drugs that reduce thyroid production may not address hormone already released from an inflamed gland. Keep any planned follow-up even if symptoms ease.

Seek urgent help for chest pain, fainting, severe breathlessness, confusion, or a very fast or irregular heartbeat with marked weakness. Prompt assessment is also needed for severe neck swelling, difficulty swallowing, or rapidly worsening illness. Contact your clinician if heat intolerance, sweating, diarrhoea, anxiety, poor sleep, or palpitations interfere with daily activities. Symptoms can overlap with other conditions, so escalation should be based on severity and change rather than assuming the cause.

Ask which thyroid tests are needed, whether your neck is tender from thyroid inflammation, how symptoms will be controlled, and when repeat testing should occur. Mention recent illness, pregnancy or pregnancy plans, heart conditions, and every medicine or supplement you use.