Thyrotoxicosis

Definition

Thyrotoxicosis is the hypermetabolic condition associated with elevated levels of free thyroxine (FT4) and/or free triiodothyronine (FT3). Hyperthyroidism includes diseases that are a subset of thyrotoxicosis, that are caused by excess synthesis and secretion of thyroid hormone by the thyroid; they are not associated with exogenous thyroid hormone intake and subacute thyroiditis. Most clinicians, exclusive of endocrinologists, use the terms hyperthyroidism and thyrotoxicosis interchangeably. The causes of thyrotoxicosis include Graves disease, an organ-specific autoimmune disorder characterized by a variety of circulating antibodies, subacute thyroiditis (approximately 15-20%), a destructive release of preformed thyroid hormone, toxic multinodular goiter (Plummer disease), toxic adenoma (a single hyperfunctioning follicular thyroid adenoma).. Symptoms present as weight loss despite enhanced appetite, heat intolerance, palpitations, tremor, and hyperdefecation.

Exclusions

• Transitory neonatal hyperthyroidism (KB62.0)

9 subordinate codes

• 5A02.0Thyrotoxicosis with diffuse goitre
• 5A02.1Thyrotoxicosis with toxic single thyroid nodule
• 5A02.2Thyrotoxicosis with toxic multinodular goitre
• 5A02.3Thyrotoxicosis from ectopic thyroid tissue
• 5A02.4Thyrotoxicosis factitia
• 5A02.5Thyroid crisis
• 5A02.6Secondary hyperthyroidism
• 4B4YOther specified diseases of the immune system
• 4B4ZDiseases of the immune system, unspecified

Nearby in Disorders of the thyroid gland or thyroid hormones system

• 5A00Hypothyroidism
• 5A01Nontoxic goitre
• 5A03Thyroiditis
• 5A04Hypersecretion of calcitonin
• 5A05Generalised resistance to thyroid hormone
• 5A06Sick-euthyroid syndrome
• 4B4YOther specified diseases of the immune system
• 4B4ZDiseases of the immune system, unspecified