Primary hypothyroidism

Last reviewed: 6 Sep 2022
Last updated: 13 Apr 2021

Summary

Definition

History and exam

Key diagnostic factors

  • presence of risk factors
  • non-specific symptoms
More key diagnostic factors

Other diagnostic factors

  • lethargy
  • constipation
  • weight gain
  • menstrual irregularity
  • dry or coarse skin
  • change in voice
  • bradycardia
  • hypertension
  • delayed relaxation of tendon reflexes
  • cold sensitivity
  • coarse hair
  • eyelid oedema
  • goitre
Other diagnostic factors

Risk factors

  • iodine deficiency
  • female sex
  • middle age
  • family history of autoimmune thyroiditis
  • autoimmune disorders
  • treatment for thyroid disease
  • post-partum thyroiditis
  • Turner's and Down's syndromes
  • type 1 diabetes
  • radiotherapy to head and neck
  • infiltrative disease
  • iodine excess
  • amiodarone use
  • lithium use
More risk factors

Diagnostic investigations

1st investigations to order

  • serum thyroid-stimulating hormone (TSH)
More 1st investigations to order

Investigations to consider

  • free serum T4
  • antithyroid peroxidase antibodies
  • FBC
  • fasting blood glucose
  • serum cholesterol
  • homocysteine
More investigations to consider

Treatment algorithm

ONGOING

confirmed overt primary hypothyroidism

sub-clinical 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

Bernard Ewigman, MD

Professor of Medicine

Chair of Family Medicine

University of Chicago Medical Center

Chicago

IL

Disclosures

BE declares that he 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.

Joaquin Lado, MD, PhD

Professor of Internal Medicine

Endocrinology Division Chief

Texas Tech University Health Sciences Center - School of Medicine

Lubbock

TX

Disclosures

JL declares that he has no competing interests.

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