Hypothyroidism Flashcards
(19 cards)
What are the causes of Primary Hypothyroidism?
- Hashimoto’s thyroiditis (most commonin developed wrold)
- Primary atrophic hypothyroidism
- Iodine deficiency (most common worldwide)
- Post thyroidectomy/radioiodine tx
- Drug induced
- Carbimazole
- Prophylthiouracil
- Lithium
- Amiodarone
- de Quervain’s Thyroiditis
What are the causes of secondary Hypothyroidism? (central hypothyroidism)
- Hypopituitarism (very uncommon)
- Sheehan syndrome
- tumours
- infection
- radiation
What causes tertiary hypothyroidism?
- Trauma or lesion at hypothalamus
- affects production of TRH
What demographic of patients hypothyroidism commonly affects?
- Female
- 40 years or more
What are the Sx of hypothyroidism?
- Tiredness
- Sleepy
- Lethargic
- Low mood
- Cold disliking
- Weight gain
- consipation
- menorrhagia
- hoarse voice
- decrease memory
- myalgia
- cramps/weakness
What are the clinical signs of hypothyroidims?
*remember mnemoni bRADYCARDIC
- Reflexes - slow
- Ataxia
- Dry brittle hair, skin
- Yawning
- Cold hands
- Ascites
- Round puffy face
- Defeated demeanour
- Immobie
- CCF
What are the Ix interpretation for Hypothyroidism?
- Primary Hypothyroidism
- TSH: high
- T4&T3: low
- Secondary Hypothyroidism
- TSH: low
- T4&T3: low
What other diseases is seen associated with Hypothyroidism?
- If autoimmune cause - think other autoimmune disease
- T1DM
- Addison’s disease
- Turner’s, Downs
- CF
- Primary Biliary cholangitis
- POEMS syndrome
How would you Mx Hypothyroidism?
- Levothyroxine
- 1.6mcg/kg/day for <65
- 25-50mcg/day for 65 and >
What is the Cx of Hypothyroidism?
- Myxoedema Coma
What is the Wolff-Chaikoff effect?
- Too much iodine
- Iodine inhibits thyroid hormone production (initially)
- Eventually, thyroid will resume production
What is the Px of Hashimoto’s Thyroiditis?
- anti-TPO and antithyroglobulin antibodies infiltrate thyroid
- Causes goitre initially
- Atrophy later on
What gene is associated with Hashimoto’s thyroiditis?
- HLA-DR3
What is subclinical hypothyroidism?
- TSH >4mU/L
- T4&T3 normal
- no sx
What age group does subclinical hypothyroidism typically affects?
- >55
How would you Mx subclinical hypothyroidism?
- confirm raised TSH persistent (recheck in 2-4months)
- recheck sx of hypothyroidims
What is the presentation of Myxedema Coma?
- A reduced level of consciousness
- Seizures
- Hypothermia
- Features of hypothyroidism
What is sick euthyroid syndrome?
- condition in which serum levels of thyroid hormones are low with nonthyroidal systemic illness.
- Common in hospital inpatients
- T3 is particularly low in these patients
