🦋 Hashimoto’s Disease Explained

This page explains the causes and symptoms of Hashimoto’s disease, how thyroid antibody tests help with diagnosis, and the treatment options used to manage low thyroid function.

The Most Common Cause of Low Thyroid 

If you or someone you know has hypothyroidism, there’s a good chance the cause is Hashimoto’s disease.

It is by far the most common reason people develop an underactive thyroid.

🔎 What Is Hashimoto’s Disease? 

Hashimoto’s disease (also called Hashimoto’s thyroiditis) is an autoimmune condition.

That means:

➡ Your immune system mistakenly attacks your thyroid gland.

Over time, this damage makes the thyroid unable to produce enough hormone.

🧠 What Happens in the Body 

In Hashimoto’s:

• The immune system creates thyroid antibodies
  
  

• These antibodies slowly damage thyroid cells
  
  

• The thyroid gradually loses function
  
  

• Thyroid hormone levels drop
  
  

This process usually happens slowly over months or years.

📌 Why It Happens 

Doctors don’t know one exact cause, but several factors play a role:

• Genetics (it often runs in families)
  
  

• Being female
  
  

• Hormonal changes
  
  

• Stress
  
  

• Certain infections
  
  

• Environmental factors
  
  

It is much more common in women than in men.

👩 Who Gets Hashimoto’s? 

Hashimoto’s is most common in:

• Women
  
  

• People between ages 30–60
  
  

• Those with a family history of thyroid disease
  
  

• People with other autoimmune conditions
  
  

But it can happen at any age, even in children.

😴 Common Symptoms 

The symptoms of Hashimoto’s are the same as symptoms of hypothyroidism, including:

• Tiredness
  
  

• Weight gain
  
  

• Feeling cold
  
  

• Dry skin
  
  

• Hair thinning
  
  

• Constipation
  
  

• Depression or low mood
  
  

• Brain fog
  
  

• Puffy face
  
  

• Heavy periods
  
  

• Low energy
  
  

Because it develops slowly, symptoms often creep up gradually.

🦋 Goiter (Enlarged Thyroid) 

Some people with Hashimoto’s develop:

• Swelling in the front of the neck
  
  

• A feeling of fullness in the throat
  
  

• A visible enlarged thyroid (called a goiter)
  
  

This happens because the immune attack causes inflammation.

🧪 How Hashimoto’s Is Diagnosed 

Diagnosis usually involves:

Blood Tests

Typical pattern:

• High TSH
  
  

• Low or normal Free T4
  
  

• Positive thyroid antibodies

Antibody Tests Used

• TPO antibodies (anti-TPO) – most important
  
  

• Thyroglobulin antibodies (TgAb)
  
  

A positive TPO test strongly suggests Hashimoto’s.

Sometimes Imaging

Doctors may also order:

• Thyroid ultrasound
  
  

• Especially if there is swelling or nodules

🧩 Can You Have Hashimoto’s With Normal Labs? 

Yes.

Some people have:

• Positive antibodies
  
  

• Normal TSH and T4
  
  

This means the autoimmune process has started, but the thyroid still works.

Doctors usually just monitor in this situation.

💊 Treatment for Hashimoto’s 

There is no cure for the autoimmune process itself.

Treatment focuses on replacing missing thyroid hormone.

Main Treatment

➡ Levothyroxine (synthetic T4)

This medication:

• Replaces what the thyroid can’t make
  
  

• Brings TSH back to normal
  
  

• Relieves symptoms
  
  

• Is taken once daily

What Treatment Does NOT Do

• It does not remove antibodies
  
  

• It does not “cure” Hashimoto’s
  
  

• But it effectively treats the hormone deficiency

🕒 Long-Term Outlook 

Hashimoto’s is usually:

• A lifelong condition
  
  

• Very manageable
  
  

• Easily treated with medication
  
  

Most people live completely normal, healthy lives once treated.

🌱 Lifestyle and Hashimoto’s 

While lifestyle changes cannot cure Hashimoto’s, many people feel better with:

• Balanced nutrition
  
  

• Regular exercise
  
  

• Good sleep habits
  
  

• Stress management
  
  

• Taking medication consistently
  
  

There is no special diet proven to cure Hashimoto’s.

❗ Important to Know 

Antibody levels can stay positive for years

High antibodies alone don’t require treatment

Treatment decisions are based on TSH and symptoms

🧭 What Usually Happens Next 

If you’re diagnosed with Hashimoto’s, the usual plan is:

1. Start thyroid hormone medication if needed
   
   

2. Recheck labs in 6–8 weeks
   
   

3. Adjust dose gradually
   
   

4. Monitor long term
   
   

Once stable, testing is usually once or twice a year.

🔑 Big Takeaways 

Hashimoto’s is an autoimmune attack on the thyroid

It is the most common cause of hypothyroidism

Diagnosis uses TSH and antibody tests

Treatment is thyroid hormone replacement

It is very treatable and manageable

Coming Up Next 

The next page will cover the most common cause of high thyroid:

➡ Graves’ Disease Explained