• pain in the front of the neck
• tenderness when gentle pressure is applied to the thyroid gland (palpation)
• fever
• weakness
• fatigue

Other symptoms may include:

• nervousness
• heat intolerance
• weight loss
• sweating
• diarrhea
• tremor
• palpitations

Laboratory tests in the early phase of disease may reveal:

• High serum thyroglobulin level
• Low radioactive iodine uptake
• Low serum thyroid stimulating hormone (TSH) level
• High serum free T4 (thyroid hormone, thyroxine) level
• High erythrocyte sedimentation rate (ESR)

Laboratory tests in the later phase of disease may show:

• High serum TSH level
• Low serum free T4

Anti-thyroid antibodies are either undetectable or present at low levels. Thyroid gland biopsy shows characteristic "giant cell" inflammation. Laboratory abnormalities return to normal as the condition resolves.