Can over‑replacement with levothyroxine cause a globus sensation?

Does Overtreatment with Levothyroxine Cause Globus Sensation?

Overtreatment with levothyroxine does not directly cause globus sensation based on available evidence. The FDA drug label and clinical guidelines extensively document the adverse effects of levothyroxine overtreatment—including cardiovascular complications, bone loss, and metabolic disturbances—but globus sensation is not listed among these effects 1.

Understanding the Relationship Between Thyroid and Globus

The connection between thyroid pathology and globus symptoms relates to structural thyroid enlargement, not thyroid hormone excess:

• Physical thyroid nodules or goiter can cause globus symptoms through mechanical compression. Nodules larger than 3 cm and those located anterior to the trachea are most likely to produce this sensation 2
• Among patients undergoing thyroid surgery, approximately one-third report globus symptoms preoperatively, with 80% experiencing resolution after surgical removal of the thyroid mass 3
• Patients with inflammatory thyroid pathology show the greatest improvement in globus symptoms following thyroidectomy 3

What Overtreatment with Levothyroxine Actually Causes

The documented adverse effects of levothyroxine overtreatment (TSH <0.1 mIU/L) include:

• Cardiovascular: Increased heart rate, cardiac wall thickness, arrhythmias (particularly atrial fibrillation), and angina—especially in elderly patients and those with underlying heart disease 1
• Skeletal: Accelerated bone resorption and decreased bone mineral density, particularly in postmenopausal women 1
• Metabolic: Worsening glycemic control in diabetic patients 1
• Affective: Possible mood disturbances 4

Clinical Management of Overtreatment

When TSH is suppressed (<0.1 mIU/L) in levothyroxine-treated patients without thyroid cancer or nodules requiring suppression:

• Reduce the levothyroxine dose to bring TSH into the normal reference range 5
• This is particularly important in elderly patients, who face 4-fold increased risk of overtreatment 6
• Each 25 μg increase in levothyroxine dose increases overtreatment risk 6

Key Clinical Pitfall

Do not attribute globus symptoms to thyroid hormone overtreatment. If a patient on levothyroxine develops globus sensation, investigate:

1. Structural thyroid pathology (nodules, goiter) via ultrasound
2. Laryngopharyngeal reflux (the most common cause of globus) 2
3. Other ENT pathology via laryngoscopy
4. Psychiatric factors if other causes excluded

The globus sensation in thyroid patients is a mechanical phenomenon from thyroid enlargement, not a hormonal effect from excessive levothyroxine replacement.