Which of the following conditions is most commonly associated with iodine deficiency / goiter development?

AIIMS M.Sc. Nsg Entrance exam-2026

Medical & Surgical Nursing

Easy

Appeared in: AIIMS M.Sc. Nsg Entrance exam-2026

Explanation

Iodine deficiency is the most common cause of goiter worldwide, referred to as endemic goiter.
The World Health Organization estimates that nearly 2 billion people have insufficient iodine intake.
The mechanism involves compensatory hypertrophy of the thyroid gland due to increased stimulation by Thyroid-Stimulating Hormone (TSH) from the pituitary gland.
When iodine is scarce, the pituitary increases TSH output to make the thyroid work harder and grow larger to trap more iodine, resulting in a goiter.

Option A: A pituitary tumor (specifically a TSH-secreting adenoma) can cause goiter by overproducing TSH, but this is an extremely rare cause compared to iodine deficiency.
Option B: While autoimmune diseases like Hashimoto's thyroiditis and Graves' disease are major causes of goiter, they are the most common causes in iodine-sufficient regions, not worldwide. Globally, iodine deficiency is more prevalent.
Option C: This describes a state, not a cause. A goiter can be present in individuals with normal thyroid hormone levels (euthyroid goiter), but 'normal thyroid function' does not explain the underlying reason for the gland's enlargement.

Visual 1: Diagram - A flowchart showing the negative feedback loop of the Hypothalamic-Pituitary-Thyroid (HPT) axis, illustrating how low iodine leads to high TSH and thyroid growth.
Visual 2: Image - A clinical photograph of a person with a large, visible goiter in the neck to help students recognize the physical manifestation.
Visual 3: Map - A world map highlighting regions with high prevalence of iodine deficiency to emphasize the concept of 'endemic goiter'.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Etiology of Goiter as background academic context rather than a clinical decision trigger.
The prevention of endemic goiter through the iodization of salt is one of the most successful public health initiatives worldwide. Nurses play a role in educating communities about nutrition.
When assessing a patient with a goiter, a priority nursing intervention is to check for signs of airway compression (stridor, difficulty breathing) or difficulty swallowing (dysphagia), as a large goiter can compress the trachea and esophagus.
What if? If the patient in the question was from the United States or another iodine-sufficient country, the most likely cause of goiter would shift from iodine deficiency to autoimmune thyroid disease (e.g., Hashimoto's thyroiditis).

How to Approach the Question

First, identify the core concept of the question, which is the cause of goiter.
Pay close attention to the keyword 'most commonly'. This implies you should consider the global prevalence, not just causes in a specific region.
Evaluate each option. Iodine deficiency is a well-known nutritional deficiency with worldwide impact.
Recall the pathophysiology: low iodine leads to low thyroid hormone, which triggers the pituitary to release more TSH, causing the thyroid to enlarge.
Compare this with other causes. Autoimmune diseases are common but geographically limited in their top-ranking status. Pituitary tumors are very rare. 'Normal function' is a state, not a cause.
Conclude that iodine deficiency is the most common cause on a global scale.

Concept Tested & Keywords

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