Thyroid

Question 1

TSH receptor antibodies are found in most patients with which disease?

Answer 1

Graves’ disease (form of autoimmune hyperthyroidism)

Question 2

What is primary hypothyroidism and what are the causes?

Answer 2

Autoimmune - hashimotos thyroiditis
Thyroid atrophy
Iodine deficiency (developing world)
Drugs (amiodarone, lithium, iodine)

Question 3

What is secondary hypothyroidism?

Answer 3

Usually due to a disorder of the pituitary gland or a lesion compressing the pituitary gland - much rarer.

Question 4

What is Hashimoto’s thyroiditis?

Answer 4

A type of primary hypothyroidism, due to autoimmune attack of the thyroid, that is associated with T1DM, Addison’s or Pernicious anaemia. It may cause transient thyrotoxicosis in the acute phase.

It often presents as a goitre in women aged 60-70 years old.

Question 5

What are the symptoms of hypothyroidism?

Answer 5

• Fatigue
• Menorrhagia
• Weight gain
• Decreased mood
• Intolerance to cold
• Constipation
• Weakness
• Dry skin/nails/hair
• Facial oedema

Question 6

How is hypothyroidism diagnosed?

Answer 6

Decreased T3/4 and increased TSH

Question 7

What hormones does the anterior pituitary produced?

Answer 7

• Thyroid stimulating hormone
• ACTH
• FSH and LH
• Growth hormone
• Prolactin
• Endorphs

Question 8

What are the symptoms of hyperthyroidism?

Answer 8

• Fatigue
• Sweating
• Irritability/anxiety
• Intolerance to heat
• Weight loss
• Diarrhoea
• Tremor
• Tachycardia
• Menstrual irregularity

Question 9

What are the signs of hyperthyroidism?

Answer 9

Agitation
Tachycardia
Warm/clammy
Brisk reflexes
Eye signs - proptosis/liflag
Thyroid acropachy (soft tissue swelling of hands and clubbing of fingers)
Pretibial myxoedema

Question 10

What are the signs of hypothyroidism?

Answer 10

Bradycardia
Reflexes relax slowly
Ataxia (coordination and balance difficulties)
Dry thin hair/skin
Ascites and non pitting oedema
Round puffy face
CCF
Goitre

Question 11

What is myxoedema?

Answer 11

Swelling of the skin and underlying tissues, giving a waxy consistency. This is associated with severe hypothyroidism

Question 12

What are the common causes of hyperthyroidism?

Answer 12

• Graves disease
• Toxic multinodular goitre
• Toxic adenoma
• Drugs (amiodarone/iodine)

Question 13

How can thyroid problems be investigated?

Answer 13

CLINICAL
BIOCHEMICAL - TSH, T4, T3
IMMUNOLOGY - thyroid peroxidase autoantibodies, TSH receptor antibodies
IMAGING - isotope scans (useful for detecting the cause of hyperthyroidism), USS (looks at nodules specifically)

Question 14

How is hyperthyroidism diagnosed?

Answer 14

Decreased TSH and increased T3/T4

Question 15

What drugs can be used to treat hyperthyroidism?

Answer 15

Inhibit fT4 to fT3 - Carbimazole, propylthioruracil
Symptom control - B blockers (propanolol)
Radioiodine (but will lead to hypothyroidism)

Question 16

What is a thyroid storm and what are the features?

Answer 16

Severe hyperthyroidisim causing tachycardia, fever, encephalopathy, fits, stroke, hypertension, D&V, circulatory collapse and death. It is a medical EMERGENCY.

Question 17

How is a thyroid storm treated?

Answer 17

Propylthiouracil
Iodine
Steroids(hydrocortisone)
Beta-blockers (propanolol)
IV fluids

Question 18

What drugs can be used to treat hypothyroidism?

Answer 18

• Levo-thyroxine

- Tri-iodothyronine

Question 19

What is a myxoedema coma?

Answer 19

Severe hypothyroidism causing hypothermia, bradycardia, coma, seizures, cyanosis, decreased BP and heart failure

Question 20

How is a myxoedema coma treated?

Answer 20

Tri-iodothyronine
Steroids (hydrocortisone)
IV fluids
Active warming for hypothermia

Question 21

What is thyroid eye disease?

Answer 21

Eye discomfort, grittiness, photophobia, afferent pupillary defect and expothalmous. This is associated commonly with Graves’ disease but can be present in any thyroid disorder.

Question 22

What is subclinical hyper/hypothyroidism?

Answer 22

When TSH levels are changed but T3/T4 are normal

Question 23

What is sick euthyroidisim?

Answer 23

This is the derangement of TFTs in any systemic illness - typically everything will be low.

Question 24

What is the most common cause of hypothyroidism in the developing world?

Answer 24

Iodine deficiency

Question 25

What is parathyroid hormone?

Answer 25

A hormone released in response to low levels of calcium in the blood which causes:

• Increased osteoclast activity (indirectly)
• Activation of vitamin D to increase absorption of calcium from the small intestine.

Question 26

What are the symptoms of hyperparathyroidism?

Answer 26

HIGH CALCIUM IN BLOOD - abdo pain, vomiting, polyuria, polydipsia, weight loss, osteoporosis, renal stones

Question 27

What causes hyperparathyroidism?

Answer 27

Primary - adenoma, hyperplasia, carcinoma (high calcium, high PTH)
Secondary - (secondary to decreased calcium) low vitamin D, chronic renal failure (low calcium, high PTH)

Question 28

What are the symptoms of hypoparathyroidism?

Answer 28

LOW CALCIUM IN BLOOD - cramps, anxious, seizures, trousseau sign (spasm)

Question 29

What causes hypoparathyroidism?

Answer 29

Primary - autoimmune gland failure, congenital (di george) (low PTH, low Ca)
Secondary - radiation, surgery

Question 30

What are some causes of diffuse goitre?

Answer 30

Iodine deficiency
Congenital
Acute thyroiditis
Autoimmune (graves, hashimotos)

Question 31

What is the most common cause of nodular goitre?

Answer 31

Toxic multinodular goitre (hypperthyroid)

Question 32

What are the DDs for a single thyroid nodule?

Answer 32

Cyst, adenoma, malignancy

Question 33

What are the complications for surgery for goitres?

Answer 33

EARLY: Recurrent laryngeal nerve palsy, haemorrhage, thyroid storm
LATE: hypothyroidism

Question 34

What are the side effects of carbimazole?

Answer 34

Mild: Hair loss, headaches, nausea, itchy
Serious: Sore throat due to bone marrow suppression

Question 35

What is tetany?

Answer 35

A condition marked by intermittent muscular spasms, caused by hypoparathyroidism and a consequent deficiency of calcium.