26/08/2026
Overcorrection of Hypothyroidism
Overcorrection occurs when treatment with levothyroxine is excessive, causing iatrogenic hyperthyroidism (exogenous thyrotoxicosis).
🔬 Laboratory findings
TSH ↓ / suppressed
Free T4 ↑ or sometimes high-normal
Free T3 may be normal or elevated
⚠️ Clinical manifestations
❤️ Cardiovascular
Palpitations
Tachycardia
Atrial fibrillation
Angina
Worsening heart failure
🧠 Neurological/Psychiatric
Anxiety
Irritability
Tremor
Insomnia
🔥 General
Heat intolerance
Sweating
Weight loss
Fatigue and muscle weakness
💩 Gastrointestinal
Increased bowel frequency or diarrhea
🦴 Long-term complications
Osteopenia/osteoporosis
Increased fracture risk, especially in postmenopausal women
💊 Management
Check TSH and free T4.
If TSH is suppressed due to excessive levothyroxine → reduce the dose.
Usually adjust by 12.5–25 micrograms/day.
Recheck TSH after about 6–8 weeks.
Consider temporary dose withholding and urgent assessment if there is severe thyrotoxicosis or significant cardiac symptoms.
High-yield: In treated primary hypothyroidism, a suppressed TSH usually indicates over-replacement with levothyroxine, unless there is another explanation such as central hypothyroidism or intentional TSH suppression after certain thyroid cancers.