Silent thyroiditis, also known as painless thyroiditis or subacute lymphocytic thyroiditis, is a temporary inflammation of the thyroid gland. Symptoms typically unfold in phases.

This thyroid disorder is usually marked by an initial overproduction of thyroid hormones (hyperthyroidism), often followed by an underactive phase (hypothyroidism), before returning to a typical, healthy state.

It’s considered an autoimmune-mediated condition, often grouped with postpartum thyroiditis, and may share features with Hashimoto’s thyroiditis — though silent thyroiditis tends to resolve on its own.

The symptoms will depend on the phase of silent thyroiditis you’re in. Each phase typically lasts about 2–3 months, but timing can vary.

The hyperthyroid phase may include symptoms like:

Then, you’ll transition to the hypothyroid phase. Your symptoms may shift to:

It’s usually painless, so many people may not notice symptoms or delay seeking care.

Silent thyroiditis appears to stem from an autoimmune reaction, where immune cells target and inflame the thyroid gland.

You may be more likely to develop silent thyroiditis if you’re post-partum (12–16 weeks after childbirth) or if you have another autoimmune thyroiditis condition, like Hashimoto’s disease.

Genetic factors may play a role in your risk of developing thyroiditis, but there isn’t enough research on the matter for us to fully understand it.

Around 5% of the broader population may experience autoimmune thyroid conditions, but the exact prevalence of silent thyroiditis remains less certain.

Silent thyroiditis is typically diagnosed by a general practitioner or an endocrinologist (a doctor specializing in hormone health).

If you suspect you have a thyroid condition, the health practitioner may start by asking about your medical history and symptoms. They may also try to rule out other potential causes of your symptoms.

Diagnosis typically involves:

Additional tests may include antibody panels (e.g., anti‑thyroid peroxidase), especially if you might have an autoimmune disease.

Although silent thyroiditis generally resolves on its own, certain medications and lifestyle modifications may help you manage the symptoms.

During the hyperthyroid phase, doctors often prescribe beta-blockers (like propranolol) to manage symptoms such as a fast heart rate and tremors.

In the later hypothyroid phase, if symptoms are bothersome or hormone levels are low, you might be prescribed temporary thyroid hormone replacement (like levothyroxine) for several months.

Silent thyroiditis is generally not treated with antithyroid drugs, surgery, or radioiodine, as the condition usually resolves on its own.

In many cases, silent thyroiditis resolves naturally without treatment in 3 to 12 months.

But if you don’t treat the symptoms, it may impact your quality of life. For example, symptoms like palpitations or fatigue can affect your day-to-day functioning.

Sometimes, the hypothyroid phase is drawn out, requiring hormone therapy. In rare instances, hypothyroidism may become permanent.

Silent thyroiditis is a temporary, autoimmune-mediated inflammation of the thyroid that unfolds in phases: starting with hyperthyroidism, shifting into hypothyroidism, and typically returning to typical function.

It’s usually painless and often seen in people assigned female at birth, especially after pregnancy and delivery. Most people recover fully within a year, though follow-ups are important to catch any lingering thyroid dysfunction.

Ultimately, the outlook is good. If you experience unusual symptoms — like palpitations, fatigue, or weight changes — discussing them with a healthcare professional can help clarify whether silent thyroiditis or another condition might be at play.