Hypothyroidism & Hashimoto’s Flashcards
Definition of hypothyroidism
Clinical effect of lack of thyroid hormone
What is primary and secondary hyperthyroidism?
Primary = abnormal decreased thyroid function
Secondary = abnormal decreased TSH production
Epidemiology of hypothyroidism
Women mainly
>40 years old, post partum
F:M 6:1
Pathology of hypothyroidism
Antithyroid peroxidase (Anti TPO) antibodies increased therefore attack thyroid
Causes of hypothyroidism
Hashimotos (mc in developed world)
Iodine deficiency (mc in developing world)
Treatment for hyperthyroidism (eg, carbimazole or Propylthiouracil)
Meds (lithium, amiodarone)
Secondary cause: hypopituitarism
How does hashimotos cause hypothyroidism ?
Autoimmune thyroid destruction, inflammation- goitre then atrophy of thyroid gland
How does iodine deficiency and lithium cause hypothyroidism?
Iodine - essential for thyroid hormones
Lithium- inhibits thyroid hormone
What is postpartum thyroiditis?
Same mechanism as hashimotos but
1. Acute - presents during pregnancy
2. Resolves by itself within one year of symptoms
Signs and symptoms of hypothyroidism?
BRADYCARDIC
bradycardia
Reflexes
Ataxia
Dry hair/skin
Yawning
Cold hands
Ascites
Round face (puffy)
Defeated demeanor
Immobile
Congestive heart failure
Goitre - hashimotos and I deficiency
Diagnosis?
TFTs
What would be seen in
1^ hypothyroidism
2^ hypothyroidism
Subclinical hypothyroidism
Increased TSH, decreased T3/4
Decreased TSH, decreased T3/4
Increased TSH = T4
What is the treatment for hypothyroidism?
Levothyroxine (T4, metabolizes in body to T3)
Why do you need to be careful with the dose of levothyroxine?
Often can cause iatrogenic hyperthyroidism
Titrate to effect (top up T4 when needed)
What is a complication of hypothyroidism?
Side effects
Treatment
Myxoedema coma (often infection precipitated), rapidly decreased T4
Hypothermia, loss of consciousness, heart failure
Treatment , levothyroxine, antibiotics and hydrocortisone ( until adrenal insufficiency has been ruled out)
