Overview
Definition
Underactive thyroid gland, most commonly due to autoimmune destruction.
Epidemiology
Very common, affecting ~5% of population (mostly women).
Etiology & Risk Factors
- Hashimoto's thyroiditis
- Iodine deficiency
- Iatrogenic (post-surgery/radiation)
Clinical Symptoms
- Fatigue
- Weight gain
- Cold intolerance
- Constipation
- Dry skin
Clinical Approach
Diagnosis
- High TSH
- Low Free T4
- Anti-TPO antibodies
Management
- Levothyroxine (Synthroid) replacement
Complications
- Myxedema coma
- Heart failure
- Infertility