In simple words: This code describes a condition where the thyroid gland in your neck shrinks due to factors developed after birth, like an autoimmune disease or radiation therapy. This shrinkage makes the gland less active and it can’t produce enough thyroid hormone, leading to hypothyroidism.

Acquired atrophy of the thyroid gland refers to the reduction in thyroid tissue due to causes acquired after birth, resulting in an underactive thyroid gland that does not produce enough thyroid hormone. These acquired causes can include autoimmune diseases, certain genetic diseases, history of head or neck irradiation, treatment with certain drugs, and age over 65.

Example 1: A 68-year-old female patient presents with fatigue, weight gain, and constipation. Blood tests reveal low levels of T3 and T4, and elevated TSH. An ultrasound of the thyroid shows reduced gland size, consistent with acquired atrophy., A 45-year-old male with a history of radiation therapy to the neck for Hodgkin's lymphoma develops hypothyroidism symptoms. Diagnostic testing and imaging confirm thyroid atrophy., A 30-year-old female with Hashimoto's thyroiditis (an autoimmune disease) experiences progressive thyroid atrophy and hypothyroidism, requiring hormone replacement therapy.

Documentation should include the cause of the atrophy (if known), clinical findings, lab results (thyroid function tests), imaging findings (if performed), and treatment plan.