Thyroid disorders are a group of medical conditions that affect the thyroid gland, a small but vital organ located in the neck. The thyroid gland plays a crucial role in regulating various bodily functions, making it a key component of the endocrine system. These disorders can have a significant impact on a person’s health and well-being.
The International Classification of Diseases (ICD) is a vital tool in the medical field for classifying and coding various diseases, including thyroid disorders. In this article, we will explore in detail what the ICD is, some thyroid disorders and their symptoms, and the overall classification of thyroid disorders in the ICD.
Thyroid Disorders: A brief overview
The thyroid gland produces hormones, primarily thyroxine (T4) and triiodothyronine (T3), which control metabolism, energy production, and the functioning of various organs of the body. When this gland does not function properly, it can lead to a range of disorders such as:
Hypothyroidism
- In this condition, the thyroid gland produces insufficient hormones, leading to a slowing down of the body’s processes such as energy metabolism.
- Symptoms typically include fatigue, weight gain, depression, and cold intolerance.
Hyperthyroidism
- This condition is characterized by an excessive production of thyroid hormones, causing an acceleration of metabolic processes.
- Symptoms may include weight loss, anxiety, rapid heart rate, and heat intolerance.
Goiter
- A goiter is an enlarged thyroid gland, often associated with iodine deficiency.
- It may cause neck swelling and difficulty swallowing or breathing.
Thyroid Nodules
- These are lumps that form in the thyroid gland. They can be either benign (non-cancerous) or malignant (cancerous).
- Nodules are often detected through imaging tests or physical examination.
Thyroiditis
- Thyroiditis is an inflammation of the thyroid gland, which can be due to various causes, including autoimmune diseases.
- Symptoms may include neck pain, fatigue, and thyroid dysfunction.
Thyroid Cancer
- Thyroid cancer is a relatively rare but serious condition that occurs when malignant cells develop within the thyroid gland.
- The severity of the condition mainly depends on what type of thyroid cancer it is. Common types include papillary, follicular, and medullary thyroid cancer.
- The most advanced and aggressive type of thyroid cancer is known as anaplastic thyroid cancer, and it has the poorest prognosis among all types of thyroid cancers
What is the International Classification of Diseases (ICD)?
Now that we have had a cursory overview of some thyroid conditions, let’s shift our focus to what the ICD is and why it is very important.
The International Classification of Diseases (ICD) is a comprehensive global system for classifying and coding diseases, health conditions, and other medical issues. It is maintained by the World Health Organization (WHO) and is a fundamental tool for healthcare providers, researchers, and policymakers worldwide. The ICD serves several other key purposes, including tracking disease trends, managing health records, facilitating the collection of data for large-scale research, and facilitating reimbursement for healthcare services.
The ICD, however, was not always intended for the purposes mentioned above. In fact, this disease classification system was created in the late 1800s to classify causes of death. The ICD has indeed undergone many years of transformations into what it is today.
The latest version of the ICD, ICD-11, was adopted by the World Health Assembly (the decision-making body of WHO) in May 2019 and came into effect on January 1, 2022. Even though the ICD-10 has now officially been replaced by the ICD-11, the ICD-10 is currently still more widely used as the transition is expected to take a few years to be complete in many countries.
With the transition from ICD-10 to ICD-11, the latter is designed to be more comprehensive and detailed, providing a more accurate representation of health conditions, including thyroid disorders. Notable aspects of the transition from ICD-10 to ICD-11 include the introduction of new diagnoses and the refinement of diagnostic criteria of existing diagnoses.
ICD Codes: How are thyroid disorders classified?
Like other medical conditions, thyroid disorders are extensively covered in the ICD system under specific alphanumeric codes, making it easier for healthcare providers to diagnose, treat, and study these conditions. When a healthcare provider diagnoses a patient with a thyroid disorder, they assign the appropriate ICD code, which is used for billing and tracking the prevalence of these conditions in healthcare databases.
For instance, under the ICD-10 classification system, if a patient is diagnosed with hypothyroidism, the healthcare provider will assign the code E03 for this condition. This code is used in medical records, insurance claims, and public health statistics.
In the rest of this article, we will look at how thyroid disorders are classified under both the ICD-10 and ICD-11 coding systems.
For example, the ICD-10 and ICD-11 include the following codes related to thyroid disorders:
ICD-10
- E03: Other hypothyroidism
- E05: Thyrotoxicosis (hyperthyroidism)
- E06: Thyroiditis
- E04: Other nontoxic goiter
- C73: Malignant neoplasm of the thyroid gland
ICD-11
- 5A00: Hypothyroidism
- 5A01: Hyperthyroidism
- 5A02: Goiter
- 5A03: Thyroiditis
- 5A04: Thyroid neoplasms
Notice how different the codes under each version differ from the other. This is one of the reasons why upgrading from the older system to the newer version is a logistically lengthy process. In fact, the full implementation of the new ICD-11 system has been estimated to “require a minimum of 4 to 5 years of time, effort and resources” according to a review of the World Health Organization’s ICD-11 implementation and transition guide.
It is also important to emphasize that the ICD codes are updated in order to reflect changes in medical knowledge and terminology, ensuring that healthcare professionals and researchers worldwide are using a standardized and up-to-date system.
List of ICD codes for various thyroid conditions
Although we have so far identified the ICD codes of some thyroid disorders in this article, we now present a more comprehensive overview of how thyroid disorders are classified under ICD-10 and ICD-11.
Classification of Thyroid Disorders under the International Classification of Diseases, 10th Revision (ICD-10)
II Neoplasms
- C00-C97 Malignant neoplasms
- C00-C75 Malignant neoplasms, stated or presumed to be primary, of specified sites, except lymphoid, hematopoietic and related tissue
- C73-C75 Malignant neoplasms of thyroid and other endocrine glands
- C73 Malignant neoplasm of the thyroid gland
- C73-C75 Malignant neoplasms of thyroid and other endocrine glands
- C00-C75 Malignant neoplasms, stated or presumed to be primary, of specified sites, except lymphoid, hematopoietic and related tissue
IV Endocrine, nutritional and metabolic diseases
- E00-E07 Disorders of the thyroid gland
- E00 Congenital iodine-deficiency syndrome
- E00.0 Congenital iodine-deficiency syndrome, neurological type
- E00.1 Congenital iodine-deficiency syndrome, myxo edematous type
- E00.2 Congenital iodine-deficiency syndrome, mixed type
- E00.9 Congenital iodine-deficiency syndrome, unspecified
- E01 Iodine-deficiency-related thyroid disorders and allied conditions
- E01.0 Iodine-deficiency-related diffuse (endemic) goitre
- E01.1 Iodine-deficiency-related multinodular (endemic) goitre
- E01.2 Iodine-deficiency-related (endemic) goitre, unspecified
- E01.8 Other iodine-deficiency-related thyroid disorders and allied conditions
- E02 Subclinical iodine-deficiency hypothyroidism
- E03 Other hypothyroidism
- E03.0 Congenital hypothyroidism with diffuse goitre
- E03.1 Congenital hypothyroidism without goitre
- E03.2 Hypothyroidism due to medicaments and other exogenous substances
- E03.3 Postinfectious hypothyroidism
- E03.4 Atrophy of thyroid (Acquired)
- E03.5 Myxoedema coma
- E03.8 Other specified hypothyroidism
- E03.9 Hypothyroidism, unspecified
- E04 Other nontoxic goitre
- E04.0 Nontoxic diffuse goitre
- E04.1 Nontoxic single thyroid nodule
- E04.2 Nontoxic multinodular goitre
- E04.8 Other specified nontoxic goitre
- E04.9 Nontoxic goitre, unspecified
- E05 Thyrotoxicosis [hyperthyroidism]
- E05.0 Thyrotoxicosis with diffuse goitre
- E05.1 Thyrotoxicosis with a toxic single thyroid nodule
- E05.2 Thyrotoxicosis with toxic multinodular goitre
- E05.3 Thyrotoxicosis from ectopic thyroid tissue
- E05.4 Thyrotoxicosis factitia
- E05.5 Thyroid crisis or storm
- E05.8 Other thyrotoxicosis
- E05.9 Thyrotoxicosis, unspecified
- E06 Thyroiditis
- E06.0 Acute thyroiditis
- E06.1 Subacute thyroiditis
- E06.2 Chronic thyroiditis with transient thyrotoxicosis
- E06.3 Autoimmune thyroiditis
- E06.4 Drug-induced thyroiditis
- E06.5 Other chronic thyroiditis
- E06.9 Thyroiditis, unspecified
- E07 Other disorders of the thyroid
- E07.0 Hypersecretion of calcitonin
- E07.1 Dyshormogenetic goitre
- E07.8 Other specified disorders of the thyroid
- E07.9 Disorder of thyroid, unspecified
- E00 Congenital iodine-deficiency syndrome
Source: ICD-10 Version:2019
Classification of Thyroid Disorders under the International Classification of Diseases, 11th Revision (ICD-11)
02 Neoplasms
- Malignant neoplasms, except primary neoplasms of the lymphoid, hematopoietic, central nervous system or related tissues
- Malignant neoplasms, stated or presumed to be primary, of specified sites, except lymphoid, hematopoietic, central nervous system or related tissues
- Malignant neoplasms of endocrine glands
- 2D10 Malignant neoplasms of the thyroid gland
- 2D10.0 Follicular carcinoma of the thyroid gland
- 2D10.1 Papillary carcinoma of the thyroid gland
- 2D10.2 Poorly differentiated carcinoma of the thyroid gland
- 2D10.3 Undifferentiated carcinoma of the thyroid gland
- 2D10.4 Medullary carcinoma of the thyroid gland
- 2D10.Y Other specified malignant neoplasms of the thyroid gland
- 2D10.Z Malignant neoplasms of the thyroid gland, unspecified
- 2D10 Malignant neoplasms of the thyroid gland
- Malignant neoplasms of endocrine glands
- Malignant neoplasms, stated or presumed to be primary, of specified sites, except lymphoid, hematopoietic, central nervous system or related tissues
05 Endocrine, nutritional or metabolic diseases
- Endocrine diseases
- Disorders of the thyroid gland or thyroid hormone system
- 5A00 Hypothyroidism
- 5A00.0 Congenital hypothyroidism
- 5A00.00 Permanent congenital hypothyroidism with diffuse goitre
- 5A00.01 Permanent congenital hypothyroidism without goitre
- 5A00.02 Pendred syndrome
- 5A00.03 Transient congenital hypothyroidism
- 5A00.04 Congenital hypothyroidism due to iodine deficiency
- 5A61.41 Congenital central hypothyroidism
- 5A00.0Y Other specified congenital hypothyroidism
- 5A00.0Z Congenital hypothyroidism, unspecified
- 5A00.1 Iodine-deficiency-related thyroid disorders or allied conditions
- 5A00.10 Iodine-deficiency-related diffuse goitre
- 5A00.11 Iodine-deficiency-related multinodular goitre
- 5A00.1Z Iodine-deficiency-related thyroid disorders or allied conditions, unspecified
- 5A00.2 Acquired hypothyroidism
- 5A00.20 Hypothyroidism due to medicaments or other exogenous substances
- 5A00.21 Myxoedema coma
- 5A00.22 Subclinical iodine-deficiency hypothyroidism
- 5A61.40 Acquired central hypothyroidism
- 5A00.2Y Other specified acquired hypothyroidism
- 5A00.2Z Acquired hypothyroidism, unspecified
- 5A00.Z Hypothyroidism, unspecified
- 5A00.0 Congenital hypothyroidism
- 5A01 Nontoxic goitre
- 5A01.0 Nontoxic diffuse goitre
- 5A01.1 Nontoxic single thyroid nodule
- 5A01.2 Nontoxic multinodular goitre
- 5A01.Z Nontoxic goitre, unspecified
- 5A02 Thyrotoxicosis
- 5A02.0 Thyrotoxicosis with diffuse goitre
- 5A02.1 Thyrotoxicosis with a toxic single thyroid nodule
- 5A02.2 Thyrotoxicosis with toxic multinodular goitre
- 5A02.3 Thyrotoxicosis from ectopic thyroid tissue
- 5A02.4 Thyrotoxicosis factitia
- 5A02.5 Thyroid crisis
- 5A02.6 Secondary hyperthyroidism
- 5A02.Y Other specified thyrotoxicosis
- 5A02.Z Thyrotoxicosis, unspecified
- 5A03 Thyroiditis
- 5A03.0 Acute thyroiditis
- 5A03.1 Subacute thyroiditis
- 5A03.2 Autoimmune thyroiditis
- 5A03.20 Hashimoto thyroiditis
- 5A03.21 Painless thyroiditis
- 5A03.2Y Other specified autoimmune thyroiditis
- JB44.5 Postpartum thyroiditis
- 5A03.Y Other specified thyroiditis
- 5A03.Z Thyroiditis, unspecified
- 5A04 Hypersecretion of calcitonin
- 5A05 Generalised resistance to thyroid hormone
- 5A06 Sick-euthyroid syndrome
- 5A0Y Other specified disorders of the thyroid gland or thyroid hormone system
- 5A0Z Disorders of the thyroid gland or thyroid hormones system, unspecified
- 5A00 Hypothyroidism
- Disorders of the adrenal glands or adrenal hormone system
- 5A61.4 Thyroid stimulating hormone deficiency
- 5A61.40 Acquired central hypothyroidism
- 5A61.41 Congenital central hypothyroidism
- 5A61.4Y Other specified thyroid-stimulating hormone deficiency
- 5A61.4Z Thyroid stimulating hormone deficiency, unspecified
- 5A61.4 Thyroid stimulating hormone deficiency
- Disorders of the thyroid gland or thyroid hormone system
Key Takeaways
- Thyroid disorders encompass a range of conditions affecting the thyroid gland, with symptoms that can vary widely.
- Thyroid disorders can significantly affect an individual’s health, making early diagnosis and proper management essential.
- The International Classification of Diseases (ICD) is a vital tool in the field of healthcare, providing a standardized framework for diagnosing, treating, and researching thyroid disorders, as well as many other health conditions.
- The use of ICD codes simplifies medical records and facilitates communication between healthcare providers, researchers, and insurers. It also ensures consistency in diagnosis and data collection worldwide.
- For thyroid disorders, the ICD-10 codes mainly fall under the “E00-E07” range, while the ICD-11 codes mainly fall under the “5A00-5A0Z” range.
If you or someone you know is experiencing symptoms related to thyroid disorders, it is crucial to seek medical attention. Accurate diagnosis and timely treatment are essential for managing these conditions and ensuring better health and well-being.
