Painless lymphocytic thyroiditis, known more simply as painless thyroiditis or silent thyroiditis, is an autoimmune-mediated inflammation of the thyroid gland causing release of thyroid hormones and transient thyrotoxicosis. This is frequently followed by a hypothyroid phase before recovery of normal thyroid function. However, for some patients, hypothyroidism is permanent.
Thyroiditis may occur sporadically, postnatally, during drug treatment or radiation therapy, or as the result of bacterial or viral infection.
The diagnosis can be confirmed by a 4-, 6-, or 24-hour radioiodine uptake of <1% during the hyperthyroid phase of the illness.
Treatment, if needed, includes beta-blockers for the hyperthyroid phase and levothyroxine for the hypothyroid phase of the illness.
Painless lymphocytic thyroiditis, known more simply as painless thyroiditis or silent thyroiditis, is characterised by an autoimmune-mediated lymphocytic inflammation of the thyroid gland resulting in a destructive thyroiditis with release of thyroid hormone and transient thyrotoxicosis (hyperthyroidism). This is frequently followed by a hypothyroid phase before recovery of normal thyroid function.
Painless thyroiditis is part of the spectrum of autoimmune thyroid disease and is considered by many to be a variant presentation of Hashimoto's thyroiditis (also known as chronic lymphocytic or chronic autoimmune thyroiditis). This is because individuals with painless thyroiditis may progress to permanent hypothyroidism, which is a characteristic feature of Hashimoto’s thyroiditis. Other types of autoimmune thyroid disease include Graves’ disease and postnatal thyroiditis.
This topic covers painless thyroiditis only. Please see below for other related topics:
• Subacute granulomatous thyroiditis
• Overview of thyroid dysfunction
History and exam
Key diagnostic factors
- heat intolerance
- small nontender goiter
Other diagnostic factors
- weight loss
- excessive fatigue
- muscle cramps
- weight gain
- poor concentration
- cold intolerance
- postpartum period
- female sex
- thyroid peroxidase (TPO) antibodies
- imunnomodulatory therapy
- lithium therapy
- amiodarone therapy
- type 1 diabetes and other autoimmune conditions
- autoimmune family history
1st investigations to order
- thyroid-stimulating hormone (TSH)
- serum free T4 and T3
- TPO (thyroid peroxidase) antibodies
- TSH-receptor antibodies (TRAb)
- 4-, 6-, or 24-hour radioiodine uptake
- total T3/T4 ratio
Investigations to consider
- technetium-99m pertechnetate scan
- serum thyroglobulin
- thyroid biopsy
- color-flow Doppler ultrasound
thyrotoxic (hyperthyroid) phase: mild
thyrotoxic (hyperthyroid) phase: moderate
thyrotoxic (hyperthyroid) phase: severe
hypothyroid phase: mild
hypothyroid phase: moderate to severe
Petros Perros, MD
Department of Endocrinology
Newcastle upon Tyne Hospitals NHS Foundation Trust
Newcastle upon Tyne
PP has received consultancy fees, served as a member of an advisory board, and been reimbursed for attending conferences held by IBSA Institut Biochimique SA (the manufacturer of Tirosint).
Dr Petros Perros would like to gratefully acknowledge Dr Douglas S. Ross, the previous contributor to this topic. DSR declares that he has no competing interests.
John Lazarus, MA, MD, FRCP, FACE, FRCOG
Centre for Endocrine and Diabetes Sciences
Cardiff University School of Medicine
University Hospital of Wales
JL declares that he has no competing interests.
Ronald Merrell, MD
Professor of Surgery
Virginia Commonwealth University
RM declares that he has no competing interests.
- Hashimoto (chronic lymphocytic) thyroiditis
- Graves disease
- Toxic multinodular goiter
- ACR practice parameter for the performance of therapy with unsealed radiopharmaceutical sources
- 2017 guidelines of the American Thyroid Association for the diagnosis and management of thyroid disease during pregnancy and the postpartum
Underactive thyroidMore Patient leaflets
- Log in or subscribe to access all of BMJ Best Practice
Use of this content is subject to our disclaimer