Can Children Develop Hypothyroidism?

You may have heard about hypothyroidism in adults. But did you know that children of all ages can have underactive thyroids, too? Here’s what hypothyroidism can look like in children, what causes it, and how it’s diagnosed and treated.

What is hypothyroidism?

Hypothyroidism refers to an underactive thyroid. The thyroid gland is located in the front of the neck, and it’s part of the endocrine system. It makes the hormones thyroxine (T4) and triiodothyronine (T3), which play important roles in many body functions, including:

• Growth 

• Energy metabolism

• Brain development 

• Body temperature control

Thyroid disease is fairly common in adults, but it’s less common in children. But children can develop hypothyroidism at any age. They can also be born with hypothyroidism, a condition called “congenital hypothyroidism.”

What are symptoms of hypothyroidism in children?

The symptoms of an underactive thyroid are similar in children and adults. Children may experience:

• Fatigue

• Constipation

• Mild weight gain

• Cold sensitivity

• Dry skin

• Hair loss

Young babies with hypothyroidism may not have any symptoms. But babies may:

• Seem very sleepy

• Have trouble eating

• Have a hoarse cry 

• Look like they have more jaundice (yellowing of the skin and eyes)

• Be more floppy and have trouble holding their head up (decreased body tone)

What are the complications of hypothyroidism in children and teens?

Low thyroid levels will affect children differently depending on their age. Without treatment, children can develop long-lasting complications from hypothyroidism. Children who get started on treatment for hypothyroidism later are more likely to develop these complications. 

Complications of hypothyroidism in babies

Babies need thyroid hormone for brain growth and development. Children who are born with hypothyroidism can develop serious intellectual disabilities. They will also have trouble gaining weight and growing. To avoid these complications, babies need to start taking thyroid medication as soon as possible and definitely before they’re 2 weeks old. 

Complications from congenital hypothyroidism are very severe. This is why babies are screened for the condition as part of their newborn screening. Newborn screening can identify congenital hypothyroidism when a child is only a few days old, long before they develop symptoms. That way they can start treatment early.  

Complications of hypothyroidism in children

Children who develop acquired hypothyroidism typically have poor growth. This may not be obvious at first. But, over time, many parents notice that their child isn’t growing out of their clothes as fast as they used to. And healthcare providers often notice that children aren’t growing as fast as they should be for their age during routine checkups. 

Children with acquired hypothyroidism also have trouble concentrating and learning. Some children may have trouble keeping up at school while others develop hyperactivity.  

Complications of hypothyroidism in teens

Teens who develop acquired hypothyroidism often have similar symptoms to adults. But since their brain is still growing and developing, they may also notice trouble with concentration and keeping up with schoolwork. Some teens have changes in their mood and seem more down than usual. 

Thyroid hormone plays an important role in puberty and menstruation. Teens with underactive thyroids may not start puberty on time. If they’ve already started menstruating, teens with acquired hypothyroidism can develop irregular periods. 

What causes hypothyroidism in children?

Experts divide the causes of childhood hypothyroidism into two broad categories — congenital and acquired. Let’s look at each condition. 

Congenital hypothyroidism

Congenital hypothyroidism happens when a child is born with a thyroid gland that is not fully developed or doesn’t work properly. Most of the time, it’s not clear why babies are born without a fully developed thyroid. 

Acquired hypothyroidism

Acquired hypothyroidism is hypothyroidism that starts when a child is older than 2 weeks. Acquired hypothyroidism is more common than congenital hypothyroidism. 

The most common cause of acquired hypothyroidism in children and adolescents is  Hashimoto’s thyroiditis. Hashimoto’s thyroiditis is an autoimmune condition in which the immune system attacks the thyroid. 

Another cause of underactive thyroid is iodine deficiency. Iodine is an element that the thyroid uses to make thyroid hormone. Iodine deficiency isn’t common in the U.S. because iodine is added to salt. But in other parts of the world, iodine deficiency is a major cause of hypothyroidism. 

Children can also develop hypothyroidism if the pituitary gland gets damaged or injured. The pituitary gland is a part of the brain that makes thyroid-stimulating hormone (TSH). TSH tells the thyroid gland when to make thyroid hormone. The pituitary gland can be injured if children need brain surgery or radiation. It can also get injured if children develop brain injuries or brain tumors.

How do you diagnose and treat childhood hypothyroidism?

A healthcare provider can diagnose hypothyroidism with a blood test that measures thyroid hormone and TSH.

Providers use a blood test to screen newborns for hypothyroidism right after birth. If a newborn screen detects a low thyroid level, babies can start treatment right away. Children and teens can have their thyroid levels tested if they have symptoms of hypothyroidism or if they are at higher risk of developing hypothyroidism. 

Normal thyroid levels depend on a child’s age. 

These values may change a bit depending on the lab running the test. 

If the results suggest hypothyroidism, children can start treatment with thyroid hormone.  Treatment for hypothyroidism is pretty straightforward. 

The medication levothyroxine (Synthroid) is the most common treatment choice. It’s a synthetic (human-made) version of thyroid hormone meant to replace what the body isn’t making. A child’s provider will select a dose based on their weight, then they’ll monitor TSH periodically to see if the dose needs to be adjusted. The goals are to get the hormones back in the normal range and improve the child’s symptoms. 

Can a child outgrow hypothyroidism?

Some children are able to stop taking thyroid medication over time. 

About 5% to 15% of children with congenital hypothyroidism can stop taking thyroid hormone when  they turn 3 years old. To determine this, the medication is stopped and the hormone levels are rechecked after about 1 month to see if the body is able to make the hormones on its own. That will help figure out if a child needs to continue taking thyroid medication or not. 

What to do if you think your child has hypothyroidism

Talk to your child’s healthcare provider if you think your child has hypothyroidism. Let the provider know which symptoms you’ve noticed. Your provider can order a blood test to check your child’s thyroid levels. If the levels are low, your child can start treatment right away. 

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Written by:

Brian Clista, MD

Dr. Clista is a board-certified pediatrician who works in private practice in Pittsburgh, Pennsylvania. He previously served as a National Health Service Corporation Scholar in the inner city of Pittsburgh for 11 years.

Edited by:

Patricia Pinto-Garcia, MD, MPH

Patricia Pinto-Garcia, MD, MPH, is a medical editor at GoodRx. She is a licensed, board-certified pediatrician with more than a decade of experience in academic medicine.

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