What is the recommended treatment for Hashimoto's thyroiditis?

Hashimoto's Thyroiditis: Patient Information

What is Hashimoto's Thyroiditis?

Hashimoto's thyroiditis is an autoimmune condition where your immune system attacks your thyroid gland, typically causing it to become enlarged (goiter) and eventually leading to an underactive thyroid (hypothyroidism). 1, 2 This is the most common form of thyroiditis encountered in clinical practice and represents the most common cause of hypothyroidism in areas with adequate iodine intake. 2, 3

Key Features You May Experience

• Painless thyroid enlargement (goiter) - You may notice swelling in the front of your neck, though this is often painless and develops gradually. 1, 3
• Symptoms of hypothyroidism - These include fatigue, weight gain, cold intolerance, constipation, dry skin, hair loss, and difficulty concentrating. 4, 2
• Initial absence of symptoms - Many patients have no symptoms initially and are diagnosed through routine blood work showing elevated TSH levels. 1, 3

How is Hashimoto's Thyroiditis Diagnosed?

Your diagnosis is confirmed through blood tests showing elevated thyroid-stimulating hormone (TSH), normal or low thyroid hormone levels (T3 and T4), and positive thyroid antibodies—specifically anti-thyroid peroxidase (anti-TPO) antibodies. 1, 2

• Elevated TSH indicates your pituitary gland is working harder to stimulate an underperforming thyroid. 4, 1
• Positive anti-TPO antibodies confirm the autoimmune nature of your condition and predict a 4.3% annual risk of progression to overt hypothyroidism (compared to 2.6% in antibody-negative individuals). 4
• Multiple tests over 3-6 months are recommended before starting treatment, as 30-60% of initially elevated TSH values normalize spontaneously. 4, 1

Treatment Approach

Levothyroxine (synthetic thyroid hormone) is the standard treatment for Hashimoto's thyroiditis when hypothyroidism develops, and this medication is typically required for life. 1, 2, 5

When Treatment is Started

• TSH >10 mIU/L - Treatment with levothyroxine is recommended regardless of whether you have symptoms, as this level carries approximately 5% annual risk of progression to overt hypothyroidism. 4, 1
• TSH 4.5-10 mIU/L with symptoms - Treatment may be beneficial if you experience fatigue, weight gain, cold intolerance, or other hypothyroid symptoms, particularly if you have positive anti-TPO antibodies. 4, 1
• TSH 4.5-10 mIU/L without symptoms - Your doctor may recommend monitoring thyroid function every 6-12 months rather than immediate treatment. 4

Levothyroxine Dosing

• For patients under 70 years without heart disease - The typical starting dose is approximately 1.6 mcg/kg of body weight daily, which rapidly normalizes thyroid function. 4, 1
• For patients over 70 years or with heart disease - A lower starting dose of 25-50 mcg daily is recommended, with gradual increases to avoid cardiac complications. 4, 1
• Dose adjustments are made in 12.5-25 mcg increments based on TSH levels checked every 6-8 weeks until stable. 4, 1

Special Formulations for Absorption Problems

If you have gastrointestinal conditions (such as gastroparesis, celiac disease, or inflammatory bowel disease) or multiple food/medication sensitivities, levothyroxine oral solution (Tirosint-SOL) may provide better absorption than tablets. 6 This formulation contains only levothyroxine, water, and glycerol, making it suitable for patients with absorption issues or multiple allergies. 6

Monitoring Your Treatment

Initial Phase (First 6-8 Months)

• TSH and free T4 checked every 6-8 weeks after each dose adjustment until your levels stabilize within the target range (TSH 0.5-4.5 mIU/L). 4, 1
• Symptom assessment at each visit to ensure your hypothyroid symptoms are improving. 4

Long-Term Monitoring

• TSH checked every 6-12 months once you're on a stable dose and feeling well. 4, 1
• More frequent monitoring if you develop new symptoms, change medications, become pregnant, or experience significant weight changes. 4

What to Expect Long-Term

Most patients with Hashimoto's thyroiditis require lifelong levothyroxine therapy, as spontaneous recovery of thyroid function is uncommon once overt hypothyroidism develops. 2, 5

• Antibody levels may decrease over time, particularly with levothyroxine treatment, though this doesn't mean the condition has resolved. 7
• Thyroid function should be monitored periodically even if you feel well, as your levothyroxine requirements may change over time. 7
• Approximately 12 of 28 patients (43%) who are initially euthyroid will develop subclinical or overt hypothyroidism within 18 months, requiring medication. 7

Important Considerations

Medication Timing and Interactions

• Take levothyroxine on an empty stomach 30-60 minutes before breakfast for optimal absorption. 4
• Avoid taking with calcium, iron, or antacids within 4 hours, as these interfere with absorption. 4
• Consistent timing is crucial—take your medication at the same time each day. 4

Pregnancy Planning

If you're planning pregnancy, inform your doctor immediately, as levothyroxine requirements typically increase by 25-50% during pregnancy. 4 Inadequate treatment during pregnancy is associated with increased risk of preeclampsia, low birth weight, and potential neurodevelopmental effects in the offspring. 4

Risks of Overtreatment

Taking too much levothyroxine can cause iatrogenic hyperthyroidism, increasing your risk for atrial fibrillation, osteoporosis, fractures, and cardiac complications. 4 This is why regular monitoring is essential—approximately 25% of patients are unintentionally maintained on excessive doses. 4

When to Contact Your Doctor

• New or worsening symptoms such as chest pain, palpitations, tremor, heat intolerance, or unexplained weight loss (suggesting overtreatment). 4
• Persistent hypothyroid symptoms despite treatment (suggesting undertreatment). 4
• Pregnancy or plans to become pregnant. 4
• Starting new medications that may interact with levothyroxine. 4

Prognosis

With appropriate levothyroxine therapy, patients with Hashimoto's thyroiditis can expect normal thyroid function, resolution of symptoms, and excellent quality of life. 5, 3 The key to success is consistent medication adherence, regular monitoring, and open communication with your healthcare provider about any symptoms or concerns.