The thyroid gland is a very important gland found at the front your child’s neck. It isn’t usually visible, unless very inflamed. Thyroid disease is relatively common, with over 1 in 10 of us experiencing thyroid disease in our lifetimes. However, we tend to associate it with adults and not children. However, it is possible for children, including newborn babies, to have or develop thyroid disease. In many cases, an underactive thyroid in children is the cause.

What causes an underactive thyroid in children?

There are a number of different causes of an underactive thyroid in children. Hypothyroidism – when the thyroid gland is underactive – tends to run in families. As such, if there is a family history of thyroid disorders, it’s essential to keep a close eye on your child as they are at higher risk. It is also believed that families with greater prevalence of autoimmune disorders, specifically those impacting the thyroid, are at greater risk.

It would appear that an underactive thyroid in children is more commonly caused by types of autoimmune condition, such as Hashimoto’s thyroiditis or Graves’ disease. These tend to develop more commonly during puberty, rather than in younger children. They affect more girls than boys.

There are other causes of an underactive thyroid in children. An infant can be born without a fully working thyroid gland, or indeed, rarely, without a thyroid gland at all. Additionally, if the mother had untreated or poorly treated hypothyroidism in pregnancy then this can sometimes lead to an underactive thyroid in children at birth.

It’s also possible for a child to experience an underactive thyroid because they don’t get enough iodine in their diet as iodine is needed to produce thyroid hormone. Iodine is found in foods such as seafood, seaweed, eggs and iodized salt.

An abnormal pituitary gland can also lead to an underactive thyroid in children.

How to identify an underactive thyroid in children

It can often be harder to identify symptoms in someone else, rather than in yourself. It’s even harder with children, and especially babies. However, there are a number of symptoms of an underactive thyroid in children as hypothyroidism presents in some classic ways.

To make it easier to understand the symptoms of an underactive thyroid in children, we’ve split our lists of symptoms into those for newborns and young babies, children before puberty, and pubescent children and teens.

Symptoms of an underactive thyroid in babies

Symptoms of an underactive thyroid in babies can present within a few weeks after birth. Symptoms are often difficult to spot but may include:

• Constipation
• Cold skin, especially out of keeping with the environment
• Poor feeding
• Lethargy, sleeping more than expected and reduced crying
• Yellowing of skin and eyes
• Labored or loud breathing
• A large tongue
• A larger soft spot (fontanelle) on baby’s head

Symptoms of an underactive thyroid in children from toddlerhood to before puberty

It is possible for an underactive thyroid to happen after babyhood but before puberty. In these cases, the following symptoms are more evident:

• Short stature and slow growth
• Short arms and legs
• Late developing permanent teeth
• Puberty delays
• Constipation
• Reduced or slowed mental development
• Slow heart rate
• Lethargy and tiredness
• Brittle hair and dry skin
• Puffy facial features

Symptoms of an underactive thyroid in pubescent children and teens

An underactive thyroid (hypothyroidism) is more commonly found in girls than boys from puberty onwards as it’s associated with Hashimoto’s disease. Commonly, the signs and symptoms of an underactive thyroid in teens mirror the symptoms that adults experience. Their symptoms may include:

• Weight gain
• Tiredness
• Reduced or slower growth
• Short stature
• Looking young comparable with their peers
• Difficulties remembering things
• Difficulties concentrating
• Delayed puberty symptoms in girls: slowed breast development and being later to start their period
• Irregular or heavy menstrual bleeding
• Boys may have larger than normal testicles
• Dry skin, brittle hair and nails which break easily
• Constipation
• Muscle and joint stiffness and pain
• Droopy eyelids
• A puffy face
• Swelling of the neck due to a swollen thyroid gland
• Hoarse voice
• Mood or behavior problems
• Lower than expected school performance

Are some children more likely to have an underactive thyroid than others?

Certain children are at greater risk of an underactive thyroid. As already stated, family history is an important consideration. In addition, children with a chromosome disorder (for example, Down syndrome, Turner syndrome or Williams syndrome) are at increased risk. Children with diabetes also have a greater risk of having an underactive thyroid. Those with celiac disease appear to be at increased risk of hypothyroidism too.

How is an underactive thyroid in children diagnosed?

It is essential that your child sees a doctor for accurate diagnosis of hypothyroidism. The doctor will usually undertake a physical examination which will likely involve feeling the front of the neck where the thyroid is located. They may also weigh and measure the child. They may go on to do blood tests which look at the amount of thyroid hormones in the blood stream. In some cases, they may perform a scan or imaging of the front of the neck to look at the thyroid gland itself.

How to treat an underactive thyroid in children?

If the underactive thyroid is causing symptoms then the most common treatment for an underactive thyroid in children is to take replacement thyroid hormone every day. This is usually done by taking pills daily, called levothyroxine. Your doctor will adjust the dose until the hypothyroidism is adequately controlled.

It’s important to start treatment as soon as possible, especially in very young babies, to ensure that there are no developmental delays.

Treatment is effective for an underactive thyroid in treatment and management is usually very effective. It will need to be reviewed regularly, particularly during key times in development, such as puberty. Most underactive thyroid conditions require treatment for life.

At International Pharmacy, we provide information to assist you with managing yours and your child’s health. However, this information does not replace medical advice. Please consult your family doctor or healthcare practitioner for advice regarding an underactive thyroid in your child.