Have you noticed E04.1 on your thyroid ultrasound report or medical records? You may be wondering what it means and whether it indicates a serious condition.
The most commonly used thyroid nodule ICD-10-CM code is E04.1, which identifies a nontoxic single thyroid nodule. However, the correct code depends on whether the nodule is single or multiple, whether it affects thyroid hormone production, and whether another diagnosis has been confirmed.
Most thyroid nodules are benign, but some require further testing. Here’s a guide to the codes, symptoms, diagnosis, and treatment options.
What Is the ICD-10 Code for a Thyroid Nodule?
ICD-10 stands for International Classification of Diseases, Tenth Revision. ICD-10-CM is the US clinical modification used for medical diagnosis coding.
E04.1 is the ICD-10-CM code for a nontoxic single thyroid nodule.
A thyroid nodule is a lump or growth within the thyroid gland, a butterfly-shaped organ at the front of your neck.
“Nontoxic” generally means the condition is not associated with excessive thyroid hormone production. It does not automatically confirm that a nodule is noncancerous.
Thyroid Nodule ICD-10 Codes: Complete Chart
The code depends on the documented condition.
| ICD-10-CM code | Diagnosis | When it applies |
| E04.1 | Nontoxic single thyroid nodule | One nontoxic thyroid nodule |
| E04.2 | Nontoxic multinodular goiter | Multiple nodules in a nontoxic enlarged thyroid |
| E04.0 | Nontoxic diffuse goiter | General thyroid enlargement without distinct nodules |
| E04.9 | Nontoxic goiter, unspecified | Nontoxic goiter without further specification |
| E05.10 | Toxic single thyroid nodule without crisis | Hyperthyroidism associated with a toxic single nodule |
| E05.20 | Toxic multinodular goiter without crisis | Hyperthyroidism associated with toxic multinodular goiter |
| D34 | Benign neoplasm of thyroid gland | A documented benign thyroid neoplasm |
| D44.0 | Neoplasm of uncertain behavior of thyroid gland | A thyroid neoplasm documented as having uncertain behavior |
| C73 | Malignant neoplasm of thyroid gland | Confirmed thyroid cancer |
These are examples of US ICD-10-CM codes. Code selection must follow the documented diagnosis, applicable coding guidelines, and the code set for the date of service.
Important: A nodule being described as “benign-looking” on ultrasound does not automatically justify coding it as a confirmed benign neoplasm.
Single vs Multiple Thyroid Nodules: E04.1 and E04.2
Two frequently searched codes are E04.1 and E04.2.
E04.1 – Single thyroid nodule
This code applies to a documented nontoxic single thyroid nodule. The ICD-10-CM description also includes certain colloid and cystic thyroid nodules.
E04.2 – Multinodular goiter
This code applies to a documented nontoxic multinodular goiter, where multiple nodules occur in an enlarged thyroid gland.
The distinction matters because a single nodule and a multinodular goiter are different clinical descriptions.
Right and Left Thyroid Nodule ICD-10 Codes
Does the code change depending on which side of the thyroid contains the nodule?
No. ICD-10-CM code E04.1 does not specify laterality.
A nontoxic single thyroid nodule in the right lobe and one in the left lobe generally use the same code when the documented diagnosis is otherwise identical.
The ultrasound report should still record the nodule’s location, size, and characteristics.
There is no separate E04.1 code for right-sided or left-sided nodules.
What Causes Thyroid Nodules?
Thyroid nodules can develop for several reasons.
1. Thyroid Tissue Overgrowth
Some nodules develop when thyroid cells multiply and form a localised growth. Many are benign.
2. Thyroid Cysts
Cysts are fluid-filled or partly fluid-filled nodules. Some are harmless, while others need assessment based on their appearance.
3. Iodine Deficiency
Insufficient iodine can contribute to thyroid enlargement and nodular thyroid disease, particularly in iodine-deficient populations.
4. Thyroid Inflammation
Conditions such as Hashimoto’s thyroiditis can alter the thyroid gland’s structure and sometimes produce a nodular appearance.
5. Family History and Radiation Exposure
Certain inherited conditions and exposure to radiation during childhood may increase the risk of thyroid nodules or thyroid cancer.
Thyroid nodules also become more common with increasing age.
Common Symptoms of Thyroid Nodules
Many thyroid nodules cause no symptoms and are discovered during routine examinations or imaging.
Larger nodules may cause:
- A visible or noticeable lump in the neck
- Difficulty swallowing
- Pressure or discomfort in the throat
- Hoarseness or voice changes
- Breathing difficulty if the nodule compresses nearby structures
Some nodules produce excess thyroid hormones, potentially causing palpitations, tremors, sweating, or unexplained weight loss.
Seek prompt medical assessment for breathing difficulties, persistent hoarseness, or a rapidly enlarging neck lump.
How Are Thyroid Nodules Diagnosed?
A healthcare professional may recommend the following investigations.
1. Thyroid Function Tests
Blood tests, particularly thyroid-stimulating hormone (TSH), help assess thyroid function.
2. Thyroid Ultrasound
Ultrasound evaluates the number, size, composition, and appearance of nodules.
Doctors may use systems such as TI-RADS to estimate which nodules require closer evaluation.
3. Fine-Needle Aspiration Biopsy
A fine-needle aspiration (FNA) biopsy collects cells from a nodule for examination.
Not every nodule requires a biopsy. The decision depends on ultrasound features, size, and clinical risk factors.
4. Thyroid Scan
If TSH is low, a radionuclide thyroid scan may help determine whether a nodule produces excess thyroid hormone.
Treatment Options for Thyroid Nodules
Treatment depends on the diagnosis, symptoms, thyroid function, and risk of cancer.
| Treatment | When it may be considered |
| Ultrasound monitoring | Benign or low-risk nodules |
| Medication | Certain thyroid hormone disorders |
| Radioactive iodine | Selected overactive thyroid nodules |
| Radiofrequency or ethanol ablation | Selected benign symptomatic nodules |
| Surgery | Suspicious or malignant nodules, or those causing significant compression |
A biopsy is a diagnostic procedure, not a treatment. Many thyroid nodules require monitoring rather than immediate surgery.
Can Diet Help Manage Thyroid Nodules?
A balanced diet supports general thyroid health, but no specific food or diet has been proven to dissolve thyroid nodules.
Iodine is essential for thyroid hormone production. However, taking excessive iodine supplements can worsen certain thyroid disorders.
Use iodised salt in normal dietary amounts where appropriate, and avoid high-dose iodine supplements unless prescribed.
Include varied foods such as dal, eggs, dairy, vegetables, fruits, and whole grains according to your nutritional needs.
Dietary changes should complement, not replace, medical evaluation.
A Word From Fitelo
Understanding the thyroid nodule ICD-10 code can help you interpret medical documentation.
For a nontoxic single thyroid nodule, the code is E04.1. For a documented nontoxic multinodular goiter, E04.2 may apply.
However, an ICD-10 code does not independently establish whether a nodule is cancerous or determine treatment. Proper evaluation is essential.
At Fitelo, our nutrition experts can help you build balanced eating habits alongside the thyroid care recommended by your healthcare team.
Frequently Asked Questions
What Is The Icd-10 Code For A Thyroid Nodule?
E04.1 is the ICD-10-CM code for a nontoxic single thyroid nodule. Other diagnoses require different codes.
What Is The Icd-10 Code For Multiple Thyroid Nodules?
E04.2 applies to a documented nontoxic multinodular goiter. Coding depends on the exact medical record.
Is E04.1 A Cancer Diagnosis?
No. E04.1 identifies a nontoxic single thyroid nodule. It does not by itself confirm or exclude cancer.
What Is The Icd-10 Code For A Benign Thyroid Nodule?
E04.1 may apply to a nontoxic single thyroid nodule. D34 is used for a documented benign thyroid neoplasm. These descriptions are not interchangeable.
Is There A Separate Icd-10 Code For A Right Thyroid Nodule?
No. E04.1 does not distinguish between right and left thyroid nodules.
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