Thyroid goiter is most commonly caused by

Thyroid goiter is most commonly caused by

• A. Low iodine diet
• B. Autoimmune thyroiditis
• C. Excess iodine intake
• D. Radiation exposure

Answer: (A)

Low iodine intake leads to reduced thyroid hormone production. When the thyroid can’t make enough hormone, the pituitary releases more TSH. That persistent TSH stimulation drives the thyroid to grow in an attempt to capture more iodine and boost hormone synthesis, producing diffuse enlargement or a goiter. This is why iodine deficiency is the most common cause of goiter in many parts of the world. Other factors can cause thyroid enlargement, but they’re less prevalent worldwide. Autoimmune thyroiditis can enlarge the gland through immune-driven inflammation, but iodine deficiency remains the more common driver overall. Excess iodine can trigger goiter or thyroid dysfunction in susceptible individuals, and radiation exposure tends to cause nodules or other thyroid damage rather than the typical diffuse enlargement seen with iodine deficiency.

Low iodine intake leads to reduced thyroid hormone production. When the thyroid can’t make enough hormone, the pituitary releases more TSH. That persistent TSH stimulation drives the thyroid to grow in an attempt to capture more iodine and boost hormone synthesis, producing diffuse enlargement or a goiter. This is why iodine deficiency is the most common cause of goiter in many parts of the world.

Other factors can cause thyroid enlargement, but they’re less prevalent worldwide. Autoimmune thyroiditis can enlarge the gland through immune-driven inflammation, but iodine deficiency remains the more common driver overall. Excess iodine can trigger goiter or thyroid dysfunction in susceptible individuals, and radiation exposure tends to cause nodules or other thyroid damage rather than the typical diffuse enlargement seen with iodine deficiency.