Endocrine Charts

Hyperthyroidism

• Definition: Overproduction of thyroid hormones (T3 and T4), leading to an overactive thyroid.

• Common Causes:

  • Graves' disease (autoimmune condition)

  • Toxic multinodular goiter

  • Thyroiditis

  • Overuse of thyroid hormone medication

• Symptoms:

  • Weight loss

  • Increased appetite

  • Rapid heart rate (tachycardia), palpitations

  • Heat intolerance

  • Sweating

  • Tremors (shaking hands)

  • Nervousness, irritability, anxiety

  • Diarrhea or frequent bowel movements

  • Muscle weakness (especially in upper arms)

  • Menstrual irregularities (light or missed periods)

• Physical Signs:

  • Enlarged thyroid (goiter), often visible

  • Bulging eyes (exophthalmos) in Graves' disease

  • Warm, moist skin

• Thyroid Hormone Levels:

  • High T3 (Triiodothyronine) and T4 (Thyroxine) levels

Hypothyroidism

• Definition: Underproduction of thyroid hormones (T3 and T4), leading to an underactive thyroid.

• Common Causes:

  • Hashimoto's thyroiditis (autoimmune)

  • Iodine deficiency (rare in developed countries)

  • Pituitary dysfunction or hypothalamic disease (rare)

  • Post-surgical or post-radioactive iodine therapy

• Symptoms:

  • Weight gain

  • Decreased appetite

  • Slow heart rate (bradycardia)

  • Cold intolerance

  • Dry skin

  • Hair thinning or hair loss

  • Fatigue, sluggishness

  • Constipation

  • Muscle stiffness, cramps, and joint pain

  • Goiter (sometimes)

  • Heavy or prolonged menstrual periods

• Physical Signs:

  • Enlarged thyroid (goiter), often visible

  • Puffy face, especially around the eyes

  • Pale, dry, cool skin

• Thyroid Hormone Levels:

  • Low T3 and T4 levels

  • Low TSH (Thyroid-Stimulating Hormone) levels due to negative feedback

  • High TSH levels (compensatory increase to stimulate thyroid)

Treatment of Thyroid Disorders

• Hyperthyroidism Treatment:

  • Antithyroid drugs (e.g., Methimazole, Propylthiouracil)

  • Radioactive iodine therapy

  • Surgery (thyroidectomy) if indicated

  • Beta-blockers (e.g., Propranolol) for symptom control (e.g., palpitations)

• Hypothyroidism Treatment:

  • Levothyroxine (synthetic T4) medication

  • Lifestyle modifications (diet, exercise)

  • Surgery or radiation (if caused by thyroid cancer)

  • Rarely, surgery if there is a goiter obstructing airways or swallowing

Complications of Thyroid Disorders

• Hyperthyroidism Complications:

  • Cardiac arrhythmias (e.g., atrial fibrillation)

  • Osteoporosis

  • Thyroid storm (severe, life-threatening exacerbation of symptoms)

  • Increased risk of clotting (venous thromboembolism)

• Hypothyroidism Complications:

  • Cardiovascular disease (increased cholesterol, heart failure)

  • Myxedema coma (severe hypothyroidism)

  • Depression, cognitive issues (memory, concentration)

  • Infertility, menstrual irregularities

Diagnosis of Thyroid Disorders

• Hyperthyroidism Diagnosis:

  • Elevated T3 and T4 levels

  • Low TSH levels

• Hypothyroidism Diagnosis:

  • Low T3 and T4 levels

  • High TSH levels (often significantly elevated)

  • Thyroid antibodies (e.g., anti-TPO in Hashimoto's thyroiditis)

  • Ultrasound may show enlarged thyroid

  • Ultrasound or radioactive iodine scan for nodules or toxic goiter

Calcium Levels in Parathyroid Dysfunction

Hypoparathyroidism

• Definition: Insufficient production or secretion of parathyroid hormone (PTH), leading to low calcium levels.

• Common Causes:

  • Surgical removal or damage to parathyroid glands (e.g., thyroid surgery)

  • Autoimmune disease (e.g., DiGeorge syndrome)

  • Genetic disorders (e.g., pseudohypoparathyroidism)

  • Magnesium deficiency (affects PTH release)

  • Low vitamin D levels (can affect calcium and PTH function)

• Symptoms:

  • Hypocalcemia: muscle cramps, tetany (muscle spasms), and seizures

  • Tingling or numbness (especially around the mouth, fingers, and toes)

  • Chvostek's sign (twitching of facial muscles when the face is tapped)

  • Trousseau's sign (carpal spasm when blood pressure cuff is inflated)

  • Cataracts (due to prolonged hypocalcemia)

  • Fatigue and irritability

• Calcium and PTH Levels:

  • Low: Hypocalcemia (serum calcium < 8.5 mg/dL)

  • Low or undetectable: Insufficient PTH secretion

  • High: Phosphate tends to be high due to decreased PTH activity, which inhibits renal phosphate excretion.

Hyperparathyroidism

• Definition: Excessive production of parathyroid hormone (PTH), leading to high calcium levels.

• Common Causes:

  • Primary hyperparathyroidism (most common cause)

  • Parathyroid adenoma (benign tumor)

  • Parathyroid hyperplasia (enlargement of all glands)

  • Parathyroid carcinoma (rare)

  • Chronic kidney disease (secondary hyperparathyroidism)

• Symptoms:

  • Hypercalcemia: fatigue, weakness, depression, and confusion

  • Bone pain, fractures, and osteoporosis due to calcium loss from bones

  • Polyuria (frequent urination) and polydipsia (increased thirst)

  • Gastrointestinal symptoms (nausea, vomiting, constipation)

  • Hypertension (high blood pressure)

  • Nephrolithiasis (kidney stones) due to high calcium levels

• Calcium and PTH Levels:

  • High: Hypercalcemia (serum calcium > 10.5 mg/dL)

  • High: Excessive PTH secretion, despite elevated calcium levels

  • Low or normal: PTH promotes phosphate excretion in the kidneys, lowering levels

  • Normal or high phosphate: Often low due to impaired calcium absorption.

Bone Health and Kidney Function in Parathyroid Disorders

• Bone Health:

  • Bone loss may occur over time if untreated due to low calcium levels.

• Kidney Function:

  • Normal or low calcium in the urine.

• Diagnosis(s):

  • Low serum calcium, low or undetectable PTH and high phosphate

Treatment of Parathyroid Disorders

• Hypoparathyroidism Treatment:

  • Calcium supplementation (oral or IV, depending on severity)

  • Vitamin D supplementation to improve calcium absorption

  • Magnesium supplementation if deficiency is present

  • Recombinant PTH (in severe cases)

• Hyperparathyroidism Treatment:

  • Surgical removal of the overactive parathyroid gland (usually adenoma)

  • Medications (e.g., bisphosphonates or calcimimetics) to reduce calcium levels if surgery is not possible

  • Hydration and diuretics (for hypercalcemia)

Complications and Prognosis of Parathyroid Disorders

• Hypoparathyroidism Complications:

  • Seizures (due to severe hypocalcemia)

  • Cardiac arrhythmias (due to low calcium)

• Prognosis:

  • If properly treated, the prognosis is generally good, though lifelong calcium and vitamin D supplementation may be required.

• Hyperparathyroidism Complications:

  • Bone demineralization and osteoporosis due to high calcium levels and increased PTH activity

  • Increased calcium excretion in urine, possibly leading to kidney stones (nephrolithiasis)

  • Hypertension, nephrolithiasis, and gastrointestinal symptoms (nausea, vomiting).

• Prognosis:

  • Often good with treatment, though chronic hypercalcemia can lead to permanent kidney or bone damage without intervention.

Addison's Disease

• Definition: A condition where the adrenal glands produce insufficient cortisol and often aldosterone, leading to adrenal insufficiency.

• Common Causes:

  • Autoimmune destruction of the adrenal cortex (most common)

  • Tuberculosis, infections (e.g., fungal infections)

  • Adrenal gland hemorrhage or infarction

  • Genetic disorders (e.g., adrenal dysplasia, adrenoleukodystrophy)

• Symptoms:

  • Fatigue and muscle weakness

  • Weight loss despite normal or increased appetite

  • Hypotension (low blood pressure), dizziness, and fainting

  • Hyperpigmentation (darkening of skin, especially in sun-exposed areas)

  • Nausea, vomiting, and abdominal pain

  • Salt cravings due to aldosterone deficiency

  • Hyponatremia (low sodium) and hyperkalemia (high potassium)

  • Hypoglycemia (low blood sugar)

  • Depression and irritability

• Cortisol Levels:

  • Low cortisol levels (in blood and urine), usually accompanied by high ACTH levels

• ACTH Levels:

  • High ACTH (due to low cortisol levels, which leads to increased secretion of ACTH in an attempt to stimulate cortisol production)

Cushing's Syndrome

• Definition: A condition caused by prolonged high levels of cortisol in the body, often due to excess production or external sources (e.g., corticosteroid use).

• Common Causes:

  • Prolonged use of corticosteroid medications (exogenous Cushing's)

  • Cushing's disease: Pituitary adenoma secreting excess ACTH

  • Adrenal tumors or hyperplasia (overproduction of cortisol)

  • Ectopic ACTH secretion (from tumors outside the pituitary)

• Symptoms:

  • Weight gain, particularly in the face, neck, and abdomen

  • Buffalo hump (fat accumulation in the upper back and neck)

  • Moon face (round, puffy face)

  • Skin changes: thinning, bruising easily, and purple striae (stretch marks)

  • Hypertension (high blood pressure)

  • Hyperglycemia (high blood sugar, sometimes leading to diabetes)

  • Osteoporosis (weakening of bones due to prolonged high cortisol)

  • Menstrual irregularities in women

  • Hirsutism (increased facial and body hair in women)

• Cortisol Levels:

  • High cortisol levels (in blood and urine), often with low ACTH (unless due to pituitary disease)

• ACTH Levels:

  • Low ACTH in adrenal tumor-induced Cushing's, high ACTH in Cushing's disease (pituitary adenoma)

Diagnosis and Treatment of Adrenal Disorders

• Diagnosis of Addison's Disease:

  • Low cortisol levels in blood or urine

  • High ACTH levels (except in adrenal tumor cases)

  • ACTH stimulation test (to confirm adrenal insufficiency)

• Diagnosis of Cushing's Syndrome:

  • High cortisol levels in blood or urine

  • Dexamethasone suppression test (failure to suppress cortisol in Cushing's)

  • Imaging (CT/MRI) to locate pituitary, adrenal, or ectopic tumors

• Treatment of Addison's Disease:

  • Corticosteroid replacement (e.g., hydrocortisone or prednisone)

  • Mineralocorticoid replacement (e.g., fludrocortisone)

  • Salt replacement in cases of aldosterone deficiency

• Treatment of Cushing's Syndrome:

  • Surgical removal of tumor (pituitary, adrenal, or ectopic)

  • Medications to inhibit cortisol production (e.g., ketoconazole, metyrapone)

  • Radiation therapy (for pituitary adenomas or tumors)

Complications and Prognosis of Adrenal Disorders

• Complications of Addison's Disease:

  • Adrenal crisis (life-threatening, triggered by stress, illness, or injury)

  • Hyperpigmentation in skin and mucous membranes

  • Osteoporosis due to chronic low calcium

  • Death if untreated or during periods of stress without sufficient steroid replacement

• Prognosis of Addison's Disease:

  • With appropriate treatment (steroid replacement), the prognosis is generally good, but adrenal crisis can be fatal without immediate intervention.

• Complications of Cushing's Syndrome:

  • Cardiovascular problems: hypertension, increased risk of stroke

  • Psychiatric symptoms: mood swings, depression, anxiety

  • Infections (due to suppressed immune function)

  • Acid-base imbalances (e.g., metabolic alkalosis)

• Prognosis of Cushing's Syndrome:

  • With treatment (surgery, medications), the prognosis is generally good, but untreated Cushing's can lead to serious complications like cardiovascular disease, diabetes, and osteoporosis.