While auto-immune thyroiditis conditions are likely to persist, some types may be temporary, including those caused by infection, pregnancy, or medication.[¹⁸]

Rapid onset of thyroid enlargement over 12-48 hours with throat pain or tenderness and flu-like symptoms is usually thought to be viral. An initial phase of hyperthyroidism-type symptoms is followed by hypothyroidism-type symptoms. De Quervain’s thyroiditis, a subacute form, may follow on within weeks of an upper respiratory infection and is also associated with mumps, measles, flu and other viruses.[^18,19,20]

Viral thyroiditis can subside equally quickly, often helped with anti-inflammatories, but steroids may be required if pain or swelling persists. Complete recovery usually takes 2-5 months, but some people are left with persistent hypothyroidism, requiring levothyroxine therapy.[¹⁸]

Rarely, bacterial infections can cause acute or infectious thyroiditis. At risk are people with weakened immune systems or children where there is already a problem with thyroid development.[¹⁹]

Postpartum thyroiditis can occur within six months after giving birth, with the mother usually having increased levels of thyroid antibodies. This needs to be differentiated from Graves’ disease and may appear as post-partum depression. Again, a hyperthyroid-like state can precede hypothyroidism. Betablockers or levothyroxine may be useful, but most women completely recover quickly, within 6-12 months after the birth.[^18,19]

Silent or painless thyroiditis has similar features, although is not related to giving birth and can also occur in men. It may take 12-18 months to clear up but sometimes becomes permanent.[¹⁹]