Hashimoto’s disease

Hashimoto’s disease, also called chronic thyroiditis, happens when the immune system mistakenly attacks the thyroid gland. The thyroid is a small, butterfly-shaped gland at the base of your neck that controls many body functions through hormones. Over time, this immune reaction can cause damage and lead to an underactive thyroid (hypothyroidism). Hashimoto’s disease is most common in people assigned female at birth and often appears in middle age.

This condition is usually managed by endocrinologists, doctors who specialize in hormone and thyroid disorders. At Penn Medicine, you’ll find specialists with deep experience in caring for people with Hashimoto’s disease. Our experts, recognized around the world for advancing thyroid care, provide both diagnosis and ongoing management tailored to your needs.

Hashimoto’s disease often develops slowly, and many people don’t notice symptoms in the early stages. The first sign may be swelling in the front of the neck (goiter). As thyroid hormone levels decline over time, you may experience:

• Fatigue or feeling unusually tired
• Increased sensitivity to cold
• Constipation
• Dry skin or brittle nails
• Hair loss
• Heavy, irregular, or missed periods
• Difficulty with memory or concentration (brain fog)
• Muscle aches, stiffness, or joint pain

The exact cause of Hashimoto’s disease isn’t fully known, but it’s thought to develop from a mix of genetic, environmental, and lifestyle factors. These influences may make some people more likely to develop the condition than others. Researchers have identified several factors that can raise the risk, including:

• Family history: Having a close relative with Hashimoto’s or another autoimmune disease makes the condition more likely.
• Other autoimmune conditions: Type 1 diabetes, rheumatoid arthritis, lupus, or celiac disease often occur alongside Hashimoto’s.
• Excess iodine intake: Too much iodine from supplements or medications can sometimes set off thyroid problems.
• Environmental triggers: Stress, infection, certain viruses like hepatitis C, or high levels of radiation may also play a role.

There’s no cure for Hashimoto’s disease, but treatment can help manage thyroid hormone levels and relieve symptoms. Not everyone with Hashimoto’s needs medication right away. If your thyroid is still producing enough hormone, your provider may simply monitor your thyroid function with regular blood tests and checkups.

If Hashimoto’s leads to hypothyroidism, the standard treatment is thyroid hormone replacement, taken as a daily pill. This medicine contains a synthetic form of thyroxine (T4), which replaces the hormone your thyroid can no longer make. Most people need to take it for life, and regular monitoring helps your provider adjust the dose as needed. Taking too much thyroid hormone can cause side effects, like irregular heartbeats or bone loss (osteopenia), so careful follow-up is important. With the right treatment, most people with Hashimoto’s disease live healthy, active lives.

What you eat can influence Hashimoto’s disease and how well your thyroid medication works. Focusing on balanced, anti-inflammatory foods can support your immune system and help manage your symptoms. Your provider may recommend working with a dietitian who specializes in thyroid disease to create a hypothyroidism diet plan.

Certain foods, drinks, and supplements can interfere with how your body absorbs thyroid medication. To avoid this, your provider may recommend taking your medication on an empty stomach, about 30 to 60 minutes before eating. You may also be asked to limit or avoid:

• Soy products
• High-iodine foods like kelp, dulse, or other seaweed
• Foods with gluten or very high fiber
• Multivitamins with iron
• Calcium supplements
• Cholesterol-lowering medications
• Antacids with aluminum hydroxide
• Some ulcer medications

At Penn Medicine, endocrinologists at the Penn Thyroid Center specialize in diagnosing and treating thyroid disorders like Hashimoto’s disease. Our team includes experienced clinicians and leading specialists who work closely with radiologists, pathologists, and dietitians to give you a clear diagnosis and a treatment plan tailored to your needs. You’ll also have access to innovative research and clinical trials that may offer new therapies and contribute to advancing thyroid care.