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Primary hypothyroidism

Last reviewed: 10 Nov 2024
Last updated: 16 May 2024

Summary

Definition

History and exam

Key diagnostic factors

  • nonspecific symptoms
Full details

Other diagnostic factors

  • lethargy
  • constipation
  • weight gain
  • depression
  • menstrual irregularity
  • dry or coarse skin
  • change in voice
  • bradycardia
  • hypertension
  • delayed relaxation of tendon reflexes
  • cold sensitivity
  • coarse hair
  • eyelid edema
  • goiter
Full details

Risk factors

  • iodine deficiency
  • female sex
  • middle age
  • family history of autoimmune thyroiditis
  • autoimmune disorders
  • treatment for thyroid disease
  • postpartum thyroiditis
  • Turner and Down syndromes
  • type 1 diabetes
  • radiation therapy to head and neck
  • infiltrative disease
  • iodine excess
  • amiodarone use
  • lithium use
Full details

Diagnostic tests

1st tests to order

  • serum thyroid-stimulating hormone (TSH)
Full details

Tests to avoid

  • thyroid ultrasound
Full details

Tests to consider

  • free serum thyroxine (T4)
  • antithyroid peroxidase antibodies
  • CBC
  • fasting blood glucose
  • serum cholesterol
Full details

Treatment algorithm

ONGOING

confirmed overt primary hypothyroidism

subclinical hypothyroidism with TSH >10 mIU/L

Contributors

Authors

Wail Malaty, MD

Adjunct Clinical Professor

Department of Family Medicine

University of North Carolina

Chapel Hill

NC

Disclosures

WM declares that he has no competing interests.

Peer reviewers

Sun Y. Lee, MD, MSc

Assistant Professor of Medicine

Boston University School of Medicine

Boston

MA

Disclosures

SYL declares that she has no competing interests.

Salman Razvi, MD, FRCP

Consultant Endocrinologist

Queen Elizabeth Hospital

Gateshead

UK

Disclosures

SR declares that he has no competing interests.

Lakdasa Premawardhana, MBBS, FRCP, FRCPE

Consultant Physician

Caerphilly Miners' Hospital

Caerphilly

UK

Disclosures

LP declares that he has no competing interests.

Birte Nygaard, MD, PhD

Associated Professor

Consultant Endocrinologist

Herlev Hospital

University of Copenhagen

Denmark

Disclosures

BN declares that she has no competing interests.

  • Differentials

    • Central or secondary hypothyroidism
    • Depression
    • Alzheimer dementia
    More Differentials
  • Guidelines

    • Thyroid disease in pregnancy
    • Thyroid disease in pregnancy
    More Guidelines
  • Patient information

    Underactive thyroid

    Underactive thyroid: questions to ask your doctor

    More Patient information
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