Painless (silent) thyroiditis

Alternative names
Lymphocytic thyroiditis; Subacute lymphocytic thyroiditis

Painless (silent) thyoiditis is an inflammation of the thyroid gland characterized by transient hyperthyroidism, followed by hypothyroidism and then recovery.

Causes, incidence, and risk factors

The cause of this type of thyroiditis is unknown. The thyroid gland becomes infiltrated with lymphocytes (a type of white blood cell).

The disease affects women more often than men and usually develops in people between age 13 and 80. The symptoms are those of hyperthyroidism (overactivity of the thyroid gland) and may last for 3 months or less.


Symptoms in painless thyroiditis are usually mild. Most symptoms are due to hyperthyroidism and may include:

  • weight loss  
  • increased appetite  
  • nervousness, restlessness  
  • heat intolerance  
  • increased sweating  
  • fatigue  
  • muscle cramps  
  • frequent bowel movements  
  • menstrual irregularities  
  • weakness  
  • irritability  
  • palpitations

Signs and tests
A physical examination reveals an enlarged thyroid gland. The pulse (heart rate) may be rapid and the hands may shake.

  • Radioactive iodine uptake is decreased.  
  • Serum T3 and T4 are elevated.  
  • A thyroid biopsy shows infiltration with lymphocytes.

Treatment is based on symptoms. Beta-blockers (Propranolol and others) relieve rapid heart rate and excessive sweating. Generally, painless thyroiditis will resolve on its own in time.

Expectations (prognosis)
The disease is usually resolved within 1 year, with the acute phase ending in 3 months. Some people may develop hypothyroidism over time, so regular follow-up is recommended.


  • hypothyroidism

Calling your health care provider
Call your health care provider if symptoms of this disorder develop.

If you have had this disease, regular follow-up is recommended to watch for the development of hypothyroidism.

Johns Hopkins patient information

Last revised: December 5, 2012
by David A. Scott, M.D.

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