Thyroid Disorders

Drugs causing hypothyroidism
Carbimazole, methimazole, popylthiouracil
Amiodarone
Lithium

• Patient feeling feverish with excessive sweating—Thyrotoxicosis.

Reference: Davidson 23rd, Box-18.11

Stem Breakdown:

Heat intolerance, palpitations, weight loss, and diarrhoea: These symptoms are classic for hyperthyroidism, indicating increased metabolism.
Diffusely enlarged thyroid: A diffusely enlarged thyroid without nodularity is characteristic of Graves’ disease.
Low TSH and elevated free T4: These lab findings confirm hyperthyroidism, with low TSH due to feedback inhibition and high free T4 indicating excessive thyroid hormone production.
Option Analysis:

A) Graves’ disease: This is the correct diagnosis. Davidson and Harrison describe Graves’ disease as the most common cause of hyperthyroidism, characterised by a diffusely enlarged thyroid gland, low TSH, and elevated free T4. Graves' disease is caused by autoantibodies that stimulate the TSH receptor, leading to increased thyroid hormone production.
B) Subacute thyroiditis: Subacute thyroiditis can cause transient hyperthyroidism due to the release of preformed thyroid hormone, but it is usually associated with neck pain and tenderness, not a diffusely enlarged thyroid.
C) Toxic multinodular goitre: Toxic multinodular goitre causes hyperthyroidism due to the presence of multiple autonomous thyroid nodules. The thyroid gland is typically irregular and nodular, not diffusely enlarged.
D) Hashimoto’s thyroiditis: Hashimoto's thyroiditis is a common cause of hypothyroidism, not hyperthyroidism. It causes a firm, enlarged thyroid and is associated with high TSH and low T4 levels.

Reference: Davidson 23rd; P-638

Reference: Davidson 23rd; P-637

Reference: Davidson 23rd; P-634

Reference: Davidson 23rd, Page: 644 , Box : 18.14

Reference: Davidson 23rd; P-644

Less common sign in hypothyroidism
Goitre with bruit
Atrial fibrillation
Systolic hypertension/increased
pulse pressure
Cardiac failure
Hyper-reexia
Ill-sustained clonus
Proximal myopathy
Bulbar myopathy

Less common sign in hyperthyroidism
Hoarse voice
Facial features:
Purplish lips
Malar flush
Periorbital oedema
Loss of lateral eyebrows
Anaemia
Carotenaemia
Erythema ab igne
Bradycardia hypertension
Delayed relaxation of reexes
Dermal myxoedema

Reference: Davidson 23rd, Page: 644, Box : 18.14

Stem Breakdown:

Heat intolerance, weight loss, palpitations: These symptoms suggest hyperthyroidism.
Diffuse thyroid enlargement and exophthalmos: These signs strongly indicate Graves’ disease, an autoimmune form of hyperthyroidism where antibodies stimulate the thyroid to overproduce thyroid hormone.
Option Analysis:

A) Propylthiouracil (PTU): PTU is an antithyroid medication used to inhibit thyroid hormone synthesis. While it is an important treatment for Graves’ disease, it is not the first-line treatment in an acute setting. Beta-blockers are initially used to control symptoms such as palpitations and tachycardia.
B) Radioactive iodine: Radioactive iodine is a definitive treatment for Graves’ disease, as it destroys overactive thyroid tissue. However, it is not used as an initial treatment to control acute symptoms.
C) Beta-blockers: This is the correct answer. Davidson and Harrison explain that beta-blockers (e.g., propranolol) are used to manage the adrenergic symptoms of hyperthyroidism (palpitations, tremors, anxiety) while more definitive treatments (e.g., antithyroid medications or radioactive iodine) are initiated.
D) Thyroidectomy: Thyroidectomy is reserved for patients who fail medical therapy or cannot tolerate other treatments. It is not used as initial treatment for hyperthyroidism.

Reference: Davidson 23rd; P-649

It will be cold intolerance , Reference: Davidson 23rd, Box-18.7

Reference: Davidson 23rd, Page : 646

Answer: A
Explanation: Radioactive iodine therapy is the most common treatment for Graves’ disease. Davidson explains that radioactive iodine selectively destroys thyroid tissue, leading to reduced thyroid hormone production. Harrison notes that this therapy is particularly effective in older patients and those with contraindications to surgery. Methimazole and beta-blockers are often used as adjunctive therapies but are not definitive treatments.

Explanation: Iodine is required for synthesis of thyroid hormones

Reference: Davidson 23rd; P-637

Explanation: Option B,C, D Causes pitting oedema.

Reference: Davidson 23rd; P-637

Reference: Davidson 23rd; P-637, box: 18.8

Reference: Davidson 23rd; P-640

Reference: Davidson 23rd, Box-29.1

Reference: Davidson 23rd; P-644

Reference: Davidson 23rd; P-644

Reference: Davidson 23rd; P-644

Reference: Davidson 23rd, Page: 634, Box: 18.3

Reference: Davidson 23rd; P-642

Reference: Davidson 23rd; P-634

Reference: Davidson 23rd; P-646

Reference: Davidson 23rd; P-649

Reference: Davidson 23rd; P-634

Hypothyroidism causes weight gain, all other disorder in the option causes weight loss