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
	Polyuria	Polydipsia	Polyphagia	Weight loss	Weight gain	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

cold intolerance

puffiness

decreased sweating

coarse skin

obstructive sleep apnea (secondary to macroglossia)

carpal tunnel syndrome

Females can present with galactorrhea and menstrual disturbances

• Fever if accompanied by thyroiditis
• fatigue
• loss of energy
• lethargy
• weight gain
• decreased appetite
• cold intolerance
• dry skin
• hair loss
• sleepiness
• muscle pain
• joint pain
• weakness in the extremities
• depression
• emotional lability
• mental impairment
• forgetfulness
• impaired memory
• inability to concentrate
• constipation
• impaired fertility
• decreased perspiration
• paresthesia and nerve entrapment syndromes
• blurred vision
• decreased hearing
• fullness in the throat
• hoarseness
• neck pain
• sore throat

Signs

hypothermia; weight gain; slowed speech and movements; dry skin; jaundice; pallor; coarse, brittle, straw like hair; loss of scalp hair, axillary hair, pubic hair, or a combination; dull facial expression; coarse facial features; periorbital puffiness; macroglossia; goiter; hoarseness; decreased systolic blood pressure and 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, or both

• 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)