[Skip to Content]

Hypothyroidism and Hashimoto’s Thyroiditis

What Is the Thyroid?

The thyroid is a small gland located below the skin and muscles at the front of the neck, just at the spot where a bow tie would rest.

It's brownish red, with left and right halves (called lobes) that look like a butterfly's wings. It usually weighs less than an ounce, but helps the body do many things, such as get energy from food, grow, and go through sexual development.

What Is Thyroid Disease?

Thyroid disease is when the thyroid gland doesn't supply the proper amount of hormones needed by the body.

  • If the thyroid is overactive, it releases too much thyroid hormone into the bloodstream, causing hyperthyroidism. The body uses up energy more quickly than it should, and chemical activity (like metabolism) in the cells speeds up.
  • If the thyroid is underactive, it makes too little thyroid hormone, causing hypothyroidism. The body uses up energy more slowly, and chemical activity (metabolism) in the cells slows down.

What Is Hypothyroidism?

Hypothyroidism (or underactive thyroid) is when the thyroid gland doesn't make enough of certain important hormones. It's a common condition, especially in older women.

But kids can have it too. Some children are born with it (called congenital hypothyroidism), while others develop it later (usually late in childhood or as teens). The most common cause of hypothyroidism in kids and teens is the autoimmune disease Hashimoto's thyroiditis.

What Are the Signs & Symptoms of Hypothyroidism?

A person with mild hypothyroidism may feel just fine — in fact, the condition might cause no symptoms at all.

But if hypothyroidism isn't found and treated, symptoms can become more obvious. These include:

  • sluggishness
  • depression
  • dry skin or hair loss
  • feeling cold
  • muscle weakness
  • poor memory or difficulty concentrating
  • constipation
  • facial puffiness 
  • weight gain (even when not eating more or exercising less)
  • slowed growth
  • slow sexual development
  • irregular menstrual periods in girls

What Is Hasimoto's Thyroiditis?

Hashimoto's thyroiditis (hah-she-MOE-toes thy-roy-DYE-tiss) is an autoimmune disease that causes most cases of hypothyroidism in kids and teens.

What Happens in Hasimoto's Thyroiditis?

Hashimoto's thyroiditis (also called chronic lymphocytic thyroiditis) is a chronic (ongoing) condition where the immune system attacks the thyroid, preventing it from producing enough thyroid hormone. The thyroid responds by working harder to make enough hormones.

This, and the swelling that can happen in the gland, can make the thyroid get bigger, leading to a goiter. The thyroid can continue to change in size over months or years. Surgery is sometimes done to treat goiters, especially if the thyroid is big enough to cause problems with swallowing.

How Are Hypothyroidism and Hasimoto's Thyroiditis Diagnosed?

Hypothyroidism and Hashimoto's thyroiditis usually are diagnosed with a physical examination and blood tests that measure:

  • thyroid hormone levels
  • certain antibodies (proteins made by the immune system); in Hashimoto's some antibodies attack the thyroid gland

How Are Hypothyroidism and Hasimoto's Thyroiditis Treated?

Doctors treat an underactive thyroid with thyroid hormone replacement pills, which will bring the body's levels of thyroid hormone back to normal. This treatment is pretty simple, but it does require doctor visits once or twice a year for an exam, blood tests, and medicine adjustments as needed.

What Else Should I Know?

In rare cases, the immune system of a child with Hashimoto's can cause inflammation in the brain and nervous system. Symptoms can include strange behavior, confusion, muscle twitching, and seizures.