Hypothyroidism Flashcards
What is Hypothyroidism?
Clinical condition resulting from low levels of T3/T4
How common is Hypothyroidism?
1-2% of general population
10:1 female preponderance
What are the common causes of Hypothyroidism?
Autoimmune - Hashimoto’s, atrophic thyroditis
Prev treatment for hyperthyroidism
What are the less common causes of Hypothyroidism?
Drugs - Amiodarone, iodine excess, lithium
Iodine deficiency
Thyroiditis (often transient)
2o causes - Hypothalamic/pituitary disorders
What are the rare causes of Hypothyroidism?
Congenital agenesis
Neoplastic infiltration
What are the sx of Hypothyroidism?
Fatigue Depression/Psychosis Cold intolerance Wt gain Constipation Menorrhagia Myxoedema coma (v. rare)
What are the signs of Hypothyroidism?
Hair loss (incl outer 1/3 eyebrow) Anaemia Hoarse voice Goitre Bradycardia Hyporeflexia Dry skin
What investigations are appropriate in suspected Hypothyroidism?
FBC (macrocytic if co-morbid pernicious anaemia, microcytic if menorrhagia)
TSH (raised)
T3/T4 (low)
TPO (raised in Hashimoto’s)
Cholesterol (raised in hepatic hypothyroidism)
CK (raised in muscular hypothyroidism)
What is the management for Hypothyroidism?
Levothyroxine (L-T4)
- Start low, titrate up
- Reassess every 4-6wks until TSH in lower 1/2 ref range
What is Acute Thyroiditis?
Inflammation of thyroid
Uncommon, may follow an URTI
How does Acute Thyrotiditis present?
Fever Malaise Thyroid swelling Tenderness Thyrotoxic features (initially only, stored hormone released) Pt then develops hypothyroidism
What is the classic finding on investigation for Acute Thyroiditis?
Low/absent uptake on Technetium scanning
How is Acute Thyroiditis treated?
Propranolol during thyrotoxic phase
Simple analgesia
Pred 30mg OD
