Hypothyroidism

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Hypothyroidism Main page
Patient Information
Overview
Classification Primary hypothyroidism Hashimoto's thyroiditis Secondary hypothyroidism Tertiary hypothyroidism
Differentiating different causes of hypothyroidism
Screening
Diagnosis
History and symptoms

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Mahshid Mir, M.D. [2]

Synonyms and keywords: Myxedema; myxoedema; thyroid activity decreased; hypothyroid

Classification

• Primary hypothyroidism
  • Congenital hypothyroidism 17512233
  • Autoimmune (Hashimoto's) thyroiditis
  • Iodine deficeincy
  • Drug induced thyroiditis
    • Amiodarone
    • Lithium
    • Thionamide
    • Iodine
    • Iterferon
    • Sunitinib
    • Rifampicin
    • Thalidomide
  • Thyroidectomy
  • Radioiodine therapy
• Transient hypothyroidism 9294788
  • Subacute (de Quervain’s) thyroiditis
  • Postpartum thyroiditis

Secondary hypothyroidism

Tertiary hypothyroidism

Differential diagnosis

Disease	History and symptoms					Laboratory findings								Additional findings
						Serum glucose	Urinary Glucose	Urine PH	Serum Sodium	Urinary Glucose	24 hrs cortisol level	C-peptide level	Serum glucagon
Primary hypothyroidism	+	+	+	+	-	↑	↑	Normal	Normal	N/↑	Normal	↓	Normal	Auto antibodies present (Anti GAD-65 and anti insulin anti bodies)
Transient hypothyroidism	+	+	+	+	-	↑	↑	Normal	Normal	↑	Normal	Normal	↑	Acanthosis nigricans
	+	+	+	-	+	↑	↑	Normal	Normal	↑	Normal	Normal	N	-
	+	+	-	-	-	Normal	Normal	Normal	↓	Normal	Normal	Normal	Normal	-
	+	+	-	-	-	Normal	Normal	Normal	↑	Normal	Normal	Normal	Normal	-
Transient hyperglycemia	-	-	-	-	-	↑	↑	Normal	Normal	↑	Normal	Normal	N/↑	In hospitalized patients especially in ICU and CCU
Steroid therapy	+	-	-	-	+	↑	↑	Normal	Normal	↑	↑	N/↑	N/↑	Acanthosis nigricans,
RTA 1	-	-	-	+	-	Normal	Normal	↑	Normal	↑	Normal	Normal	Normal	Hypokalemia, nephrolithiasis
Glucagonoma	-	-	-	-	-	↑	Normal	Normal	Normal	-	Normal	Normal	↑	Necrolytic migratory erythema
Cushing syndrome	-	-	-	-	+	↑	-	Normal	↓	N/↑	↑	Normal	Normal	Moon face, obesity, buffalo hump, easy bruisibility

General feature

Symptoms

	Constituitional	Local	Reproductive	Neuropsysiological	Others	Physical exam
	cold intolerance puffiness decreased sweating coarse skin hypothermia Fever if accompanied by thyroiditis weight gain coarse, brittle, straw like hair with hair loss	obstructive sleep apnea (secondary to macroglossia)	Females can present with galactorrhea and menstrual disturbances	depression	paresthesia and nerve entrapment syndromes	decreased systolic blood pressure increased diastolic blood pressure bradycardia pericardial effusion abdominal distension ascites (uncommon) non-pitting edema (myxedema) pitting edema of lower extremities hyporeflexia with delayed relaxation ataxia
		fullness and pain in the throat and neck	infertility	emotional lability	constipation
		hoarseness sore throat		blurred vision	macroglossia
		goiter		Attention deficit	periorbital puffiness;
				slowed speech and movements

• Metabolic abnormalities associated with hypothyroidism include:
  • anemia,
  • dilutional hyponatremia,
  • hyperlipidemia,
  • reversible increase in creatinine

Complications

Myxedema coma

Rare, severe form of hypothyroidism, a life-threatening condition

• Altered mental status,
• hypothermia,
• bradycardia,
• hypercarbia, and
• hyponatremia.
• Cardiomegaly,
• pericardial effusion,
• cardiogenic shock, and
• ascites
• commonly occurs in individuals with undiagnosed or untreated hypothyroidism who is subjected to an external stress, such as low temperature, infection, or medical intervention (e.g., surgery or hypnotic drugs)