E05.00

HCC Category Mapping

What This Code Means

An enlarged thyroid gland that is producing excess thyroid hormone, causing symptoms like rapid heartbeat and weight loss, but without a thyroid storm emergency.

Coding Tips

• •The '00' fifth character indicates no thyrotoxic crisis; if crisis develops, change to E05.01
• •Document thyroid function tests (TSH, free T4) and whether the patient is on antithyroid medications

Clinical Significance

Thyrotoxicosis with diffuse goiter without thyrotoxic crisis or storm represents Graves disease, the most common cause of hyperthyroidism, in its stable (non-crisis) form. Graves disease is an autoimmune disorder where thyroid-stimulating immunoglobulins activate the thyroid-stimulating hormone receptor, causing diffuse thyroid hormone overproduction. Clinical features include tachycardia, weight loss, tremor, heat intolerance, ophthalmopathy, and pretibial myxedema.

Documentation Requirements

• ✓Documentation should confirm Graves disease or thyrotoxicosis with diffuse goiter, supported by thyroid function tests (suppressed thyroid-stimulating hormone, elevated free thyroxine and/or free triiodothyronine), thyroid-stimulating immunoglobulin levels, and clinical findings.
• ✓Treatment modality (antithyroid medications, radioactive iodine, thyroidectomy) and response should be documented.
• ✓The absence of thyrotoxic crisis must be established to distinguish from E05.01.

Commonly Confused Codes