Grading and Treatment of Hyperthyroidism
Hyperthyroidism severity is graded based on clinical symptoms and biochemical parameters, with treatment options tailored to the severity grade, ranging from observation for mild cases to hospitalization and aggressive therapy for severe cases. 1
Diagnosis and Grading of Hyperthyroidism
Hyperthyroidism is diagnosed biochemically by:
- Low TSH with elevated free T4 and/or T3 levels for overt hyperthyroidism 2
- Low TSH with normal free T4 and T3 levels for subclinical hyperthyroidism 3
Severity Grading System
Hyperthyroidism is commonly graded according to the following criteria:
Grade 1: Asymptomatic/Mild
- Biochemical abnormalities without significant symptoms
- Clinical or diagnostic observations only
- No intervention required for asymptomatic cases 1
Grade 2: Moderate
- Symptomatic with ability to perform activities of daily living (ADL)
- May require thyroid suppression therapy
- Symptoms may include anxiety, palpitations, heat intolerance 1
Grade 3: Severe
- Severe symptoms limiting self-care ADL
- May require hospitalization
- Significant impact on quality of life 1
Grade 4: Life-threatening
- Life-threatening consequences
- Urgent intervention required
- May include thyroid storm with high mortality risk 1
Treatment Based on Severity
Grade 1 (Asymptomatic/Mild)
- Continue immune checkpoint inhibitors (if applicable) for immune-related hyperthyroidism
- Monitor thyroid function every 2-3 weeks
- Beta-blockers (e.g., atenolol 25-50 mg daily or propranolol) for symptomatic relief if needed 1
- Close monitoring for transition to hypothyroidism, which commonly follows thyroiditis 1
Grade 2 (Moderate)
- Consider holding immune checkpoint inhibitors until symptoms return to baseline
- Beta-blockers for symptomatic relief
- Hydration and supportive care
- Consider endocrine consultation
- For persistent thyrotoxicosis (>6 weeks), refer to endocrinology for additional workup and possible medical thyroid suppression 1
Grade 3-4 (Severe/Life-threatening)
- Hold immune checkpoint inhibitors until symptoms resolve to baseline
- Mandatory endocrine consultation
- Beta-blockers for symptom management
- Hydration and supportive care
- Consider hospitalization in severe cases
- Inpatient endocrine consultation for additional medical therapies including:
- Steroids (in selected cases)
- Saturated solution of potassium iodide (SSKI)
- Thionamides (methimazole or propylthiouracil)
- Possible surgery in extreme cases 1
Treatment Options by Etiology
Graves' Disease
- Antithyroid drugs (methimazole preferred over propylthiouracil except in first trimester of pregnancy)
- Radioactive iodine ablation
- Surgical thyroidectomy 2, 3
Toxic Nodular Goiter
- Radioactive iodine (131I) is preferred treatment
- Thyroidectomy
- Rarely, radiofrequency ablation 2
Thyroiditis
- Self-limiting condition that typically resolves in weeks
- Supportive care with beta-blockers for symptomatic relief
- Monitor for transition to hypothyroidism, which often follows 1
Special Considerations
Subclinical Hyperthyroidism
- Treatment recommended for:
- Patients >65 years old
- Patients with persistent TSH <0.1 mIU/L
- Those at high risk for osteoporosis or cardiovascular disease 3
Thyroid Storm (Grade 4)
- Medical emergency requiring immediate hospitalization
- Aggressive treatment with:
- Beta-blockers
- Antithyroid drugs
- Iodine solutions
- Corticosteroids
- Supportive care for fever and dehydration 1
Follow-up Monitoring
- For mild cases: Monitor thyroid function every 2-3 weeks after diagnosis
- For treated cases: Repeat testing every 6-8 weeks while titrating medication
- For persistent thyrotoxicosis (>6 weeks): Refer to endocrinology 1
Common Pitfalls to Avoid
- Not all patients with elevated free T4 are truly hyperthyroid; clinical correlation is essential 4
- TSH may remain suppressed for months after the patient becomes euthyroid on treatment 4
- Free T4 may normalize or even drop below normal while T3 remains elevated (T3 toxicosis) 4
- Failure to recognize thyroid storm as a medical emergency requiring immediate intervention 1
- Overlooking the transition from hyperthyroidism to hypothyroidism in thyroiditis 1