Clinical Thyroid Disease Flashcards
Give some symptoms of hypothyroidism
Weight gain Lethargy Feeling cold Constipation Heavy periods Dry skin/hair Bradycardia Slow reflexes Goitre In severe cases - puffy face, large tongue, hoarseness, coma
Giver some symptoms of hyperthyroidism
Weight loss Anxiety/Irritability Heat intolerance Bowel frequency Light periods Sweaty palms Palpitations Hyperreflexia/tremors Goitre Thyroid eye symptoms
What are classes of thyrotoxicosis causes?
Primary
Secondary
Thyrotoxicosis without hyperthyroidism
What are the causes of primary thyrotoxicosis?
Grave’s disease (70%)
Toxic multinodular goitre (20%)
Toxic adenoma
What are the causes of secondary thyrotoxicosis?
Pituitary adenoma secreting TSH
What are the causes of thyrotoxicosis without hyperthyroidism?
Destructive thyroiditis
Excessive thyroxine administration
What proportion of hyperthyroidism is caused by Grave’s disease? Is there a gender imbalance?
75%
5:1 female:male incidence
What are the autoimmune key points in Grave’s disease?
Thyroid peroxidase antibodies
TSH receptor antibodies
What is needed to make the diagnosis?
Either hyperthyroidism together with TSH receptor (thyroid) antibodies
OR
Hyperthyroidism with symptoms like goitre, exophthalmus etc
What is the most common cause of thyrotoxicosis in the elderly? Is there Grave’s disease?
Multi-Nodular goitre
No
What are some of the potential treatment modalities in hyperthyroidism?
Anti-thyroid drugs
Surgery
Radioactive Iodine
What are the two main anti-thyroid drugs?
Carbimazole
Propylthiouracil
What are the two available drug regimes/patterns for anti-thyroid drugs? Which is usually the preferred of the two - why?
Titration regime - dose started high and then reduced gradually
Block - Replace - high dose is maintained but thyroxine gradually introduced to counter
Titration regime is usually preferred thanks to fewer side effects
What is a common side effect of anti-thyroid drugs? What is a rarer more serious side effect?
Rash
Agranulocytosis - patients must be warned that in the case of a very painful sore throat that the medication must be stopped
What are the pros and cons when comparing high dose ablative radio iodine with variable calculated radioiodine?
High dose ablative is 90% curative but causes hypothyroidism in 70% of cases
Variable calculated has a 60-90% cure rate but less incidence of hypothyroidism
What is subclinical hyperthyroidism?
The TSH is suppressed because the pituitary has detected an increase in thyroid hormone but there are normal levels of free thyroid hormone, so there may be no noticed symptoms
Compare the expected levels of TSH and thyroid hormones in primary, secondary and subclinical/compensated hypothyroidism?
Primary - high TSH, low T3 and T4
Secondary - low TSH, low T3 and T4
Subclinical - high TSH, normal T3 and T4
What is the most common endocrine disease after DM?
Hypothyroidism
What are the two general classes of causes of primary hypothyroidism?
Congenital
Acquired
What are the causes of acquired primary hypothyroidism?
Autoimmune hypothyroid
- Hashimoto’s / atrophic
Iatrogenic
- post op
- external RT
- antithyroid drugs
Chronic iodine deficiency
What are the major causes of secondary/tertiary hypothyroidism?
Pituitary damage
Hypothalamic damage
What are the two key blood tests for investigation of suspected hypothyroidism?
TSH plasma/ T4 plasma
Autoantibodies : Thyroid peroxidase antibodies
What is the main treatment for hypothyroidism?
Levothyroxine (T4) tablets
What are some contraindications which would prompt adaptation of normal hypothyroidism treatment regimes?
IHD
Pregnancy
Postpartum thyroiditis
What indicates that treatment should be started in subclinical hypothyroidism?
Consider treatment when TSH > 10 OR TSH > 5 with thyroid antibodies OR TSH elevated with symptoms
What is the requirement with regard to levothyroxine (T4) treatment during pregnancy?
Dose increase is required
What should be considered when examining goitres?
Size, shape, consistency, mobility Bruit presence Associated lymph nodes Tracheal position Clinical thyroid status
Which autoimmune diseases may cause goitre? Are these hyperthyroid or hypothyroid conditions?
Grave’s disease - hyperthyroidism
Hashimoto’s -hypothyroidism
What are some of the different types of goitre?
Multi-nodular
Diffuse
Cysts
Tumours
What is the main test for a solitary thyroid nodule?
FNA - fine needle aspiration
What is the most common type of thyroid cancer?
Differentiated papillary cancer - local lymph node spread, good prognosis
What factors are in favour of a poorer prognosis in thyroid cancer?
Aged under 16 or over 45
Tumour size
Metastases and local spread
TNM stage
What follow-up monitoring is common after thyroid cancer remission?
Thyroglobulin monitoring