Hypothyroidism Flashcards
What are the Risk Factors for Hypothyroidism? (2 things)
- Age
- Female
What are the causes of Hypothyroidism? (7 things)
- Hashimoto’s Thyroiditis (most common cause)
- Iodine Deficiency (most common cause in developing world)
- Secondary to Hyperthyroidism Treatment
- Lithium
- Amiodarone
- Pituitary failure (2ndary Hypothyroidism)
- Down’s / Turner’s Syndrome (2ndary Hypothyroidism)
How does Lithium cause Hypothyroidism?
Inhibits thyroid hormone production in Thyroid gland
How does Amiodarone cause Hypothyroidism?
Reduces T4 –> T3 conversion
(can also cause Hyperthyroidism)
What is Hashimoto’s Thyroiditis?
Chronic AI condition –> Thyroid destruction –> Hypothyroidism
What is the Pathophysiology of Hashimoto’s Thyroiditis? (2 things)
AI thyroid cell destruction by:
- CD8+ Cytotoxic T cells destroy thyroid cells
- Antibodies clart:
- TSH receptors
- Thyroglobulin (Tg)
- Thyroid Peroxidase (TPO)
What are the CF of Hypothyroidism? (12 things)
- Memory loss
- Obesity (weight gain) (puffy face + hands + feet)
- Malar flush (red cheeks) / Menorrhagia (heavy periods)
- Infertility
- Slowness (mentally + physically)
- Skin + Hair dryness
- Onset = gradual / 0 poos (constipation)
- Tiredness
- Intolerance to cold
- Raised BP / Reduced Appetite
- Energy levels dip
- Depression
MOM IS SO TIRED
Hypothyroidism everything low low
What investigations should you do for sus Hypothyroidism? (3 things)
- TSH levels (HIGH in Primary / LOW in Secondary)
- T3 + T3 levels (LOW)
- Antibodies (Tg / TPO / TSH Receptor) (HIGH in Hashimoto’s)
Why will TSH levels be HIGH in Primary Hypothyroidism?
Bc low T3 n T4 levels doing -ve fdbk on Pit
What pregnancy problems can Hypothyroidism lead to? (6 things)
- Infertility
- Eclampsia (high BP –> seizures in pregnancy)
- Prematurity
- Low birthweight
- Stillbirth
- Postpartum hemorrhage (PPH) (heavy bleeding after birth)
What are the management options for Hypothyroidism?
Oral levothyroxine (thyroid hormone replacement)
What is Levothyroxine?
Synthetic T4
Metabolises to T3 in body
What should you do when giving Levothyroxine?
Measure TSH levels monthly bc it tells you if you need to up / reduce dose
(If TSH too HIGH = increase Levothyroxine dose)
What are the Side Fx of Levothyroxine? (4 things)
- Hyperthyroidism:
- Reduced bone mineral density
- Worsening of angina
- AF
What are the complications of Hypothyroidism? (3 things)
- Myxoedema Coma (severe hypothyroidism)
- Other AI conditions (T1DM)
- B Cell Lymphoma of Thyroid gland
