PANCE Blueprint Endocrinology (7%)

Thyroid Disorders (PEARLS)

Hyperthyroidism (ReelDx)
Patient will present as → a 34-year-old female complaining of irritability and nervousness, heat intolerance with increased sweating, and weight loss despite an increase in appetite.

Hyperthyroidism is the production of too much thyroxine hormone. It can increase metabolism and accelerate the body's metabolism, causing unintentional weight loss and a rapid or irregular heartbeat

Etiology: Grave’s disease (autoimmune). Toxic adenoma, thyroiditis, pregnancy, amiodarone

Presentation: Heat intolerance, palpitations, sweating, weight loss, tremor, anxiety, tachycardia

  • Graves - Diffuse goiter with a bruit, exophthalmos, pretibial myxedema
  • Thyroid storm - Fever, tachycardia, delirium


  • TSH (best test): Decreased in primary disease (↓ TSH  and ↑ Free T4), elevated in secondary disease (↑ TSH  and ↑ Free T4)
  • T4: Elevated although may be normal
  • Thyroid radioactive iodine uptake:
    • Graves: Diffusely high uptake
    • Toxic multinodular: Discrete areas of high uptake


  • Graves: Anti-thyrotropin antibodies


  • Beta-blockers (symptomatic), methimazole/propylthiouracil, radioactive iodine, thyroidectomy
  • Thyroid storm- prompt beta-blockers, hydrocortisone, methimazole/propylthiouracil, iodine
  • Thyroidectomy- most likely complication is recurrent laryngeal nerve (hoarseness)

Antithyroid drugs during pregnancy — Propylthiouracil used to be the drug of choice during pregnancy because it causes less severe birth defects than methimazole. But experts now recommend that propylthiouracil be given during the first trimester only. This is because there have been rare cases of liver damage in people taking propylthiouracil. After the first trimester, women should switch to methimazole for the rest of the pregnancy.

  • For women who are nursing, methimazole is probably a better choice than propylthiouracil (to avoid liver side effects)
Patient will present as → a 28-year-old woman with increased fatigue and a 10-lb weight gain over the last 2 months. She states that she “feels cold” all the time, has decreased energy, and is experiencing worsening constipation. Patient has a tender thyroid, increased TSH, elevated antimicrosomal antibodies, and increased antithyroglobulin antibodies.

Etiology: Hashimoto’s (chronic lymphocytic/autoimmune), previous thyroidectomy/iodine ablation, congenital


  • Cold intolerance, fatigue, constipation, depression, weight gain, bradycardia
  • Congenital: round face, large tongue, hernia, delayed milestones, poor feeding

Labs: TSH- elevated in primary disease. Low T4 (↑ TSH and ↓ Free T4)

  • Hashimoto’s: Antithyroid peroxidase, antithyroglobulin antibodies

Treatment: Levothyroxine. Follow up with serial TSH monitoring

Thyroiditis Thyroiditis is a general term that refers to “inflammation of the thyroid gland”. Thyroiditis includes a group of individual disorders causing thyroidal inflammation but presenting in different ways.

  • Painful vs. Painless may be hypo or hyperthyroid

Hashimoto’s thyroiditis:

  • Diffusely enlarged, painless, nodular goiter

Subacute thyroiditis:

  • Young women, after a viral infection
  • Painful enlarged thyroid with dysphagia, mild fever
  • Aspirin

Postpartum thyroiditis:

  • 1-2 months of hyperthyroidism after delivery
  • Completely resolves, give propranolol for cardiac symptoms

Suppurative thyroiditis:

  • Fever, pain, redness, fluctuant mass. ↑ WBC
  • Antibiotic/surgical drainage

IM_MED_ThyroidFunctionScreeningTests_v1.2 When a patient is suspected of having an underlying thyroid condition, there is a stepwise approach to ordering thyroid function tests. The initial screening test of choice is the measurement of thyroid stimulating hormone or TSH. Depending on the value determined, measurements of thyroid hormones (serum free T3 and free T4) may be taken, with the addition of a total T4 measurement to provide further evidence towards the underlying cause. Regardless of etiology, screening tests are not always reliable in a severely ill inpatient population, and special circumstances, like pregnancy, may alter the measured value of these tests.

Thyroid Function Screening Tests Picmonic

parathyroid-gland_5110_1472585798 The parathyroid gland is a series of four small glands located in the neck on the rear surface of the thyroid gland. It serves primarily in calcium homeostasis and has a blood calcium sensor that detects when blood calcium levels are abnormally low. It responds by releasing parathyroid hormone (PTH) which stimulates osteoclasts into action. Osteoclasts resorb bone and release a large amount of calcium. This calcium enters the blood and results in increased blood calcium levels. PTH can also activate vitamin D by promoting the activity of an enzyme that converts inactive vitamin D to active vitamin D

Parathyroid Gland Overview Picmonic

thyroid-gland_5109_1475535516 The thyroid gland is a large endocrine gland that is located in the neck. It releases T3 and T4 hormones, which help the body regulate metabolism. T3 and T4 stand for triiodothyronine (T3) and thyroxine, which can sometimes be referred to as tetraiodothyronine (T4). In addition, the thyroid gland has a blood calcium sensor that helps it detect when blood calcium levels are elevated, to which it responds. The thyroid gland releases calcitonin, which builds bone, resulting in an absorption of calcium from the bloodstream. Osteoblasts are the cells responsible for bone formation.

Thyroid Gland Overview Picmonic

Pituitary adenoma and neoplasm (Prev Lesson)
(Next Lesson) Hyperthyroidism (ReelDx)
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