Hypothyroidism in Children | What You Need to Know

29.09.2025

Hypothyroidism in children

A child's physical and mental development depends on many factors: the quality of sleep, the required amount of vitamins and minerals, complete nutrition, environmental conditions, and more.

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Accordingly, even the slightest deviation from the developmental norm is the focus of attention, and we try to identify the underlying causes.

Signs to watch out for include a child's growth retardation compared to the norm for their age and a persistent lack of energy. This is often caused by hypothyroidism.

Hypothyroidism is a condition in which the thyroid gland produces insufficient amounts of thyroid hormones.

What is the thyroid gland?

The thyroid gland is a butterfly-shaped endocrine organ located on the front surface of the larynx that produces thyroid hormones - thyroxine and triiodothyronine. Thyroid hormones are actively involved in the growth and development of a child, energy production, metabolism, and the functioning of the heart and other muscles.

What causes hypothyroidism in children?

There is congenital hypothyroidism, which is present at birth, and acquired hypothyroidism, which develops later in life.

Hashimoto's thyroiditis (autoimmune) is the most common cause of acquired hypothyroidism in children and adolescents. Hashimoto's thyroiditis is an autoimmune disease in which the immune system recognizes the thyroid cells of the thyroid gland as "foreign" and begins to fight them - producing antibodies. This leads to the development of inflammation in the gland tissue.

Chronic inflammation disrupts the normal functioning of the gland and leads to a decrease in hormone production. As soon as the concentration of thyroid hormones in the blood falls below normal, the pituitary gland begins to increase the secretion of thyroid-stimulating hormone (TSH), which stimulates the thyroid gland and “forces” it to increase hormone synthesis. The exact cause of Hashimoto's thyroiditis is not known, although it often runs in families.

Less common causes of hypothyroidism in children include:

Thyroiditis – inflammation of the thyroid gland – caused by bacteria, viruses, or other microbes.
Surgical removal of the gland
Radiation treatment (for Hodgkin's disease, lymphomas, Graves' disease, etc.)
Lithium, amiodarone, oxcarbazepine and other medications – cause decreased thyroid function
Iodine excess or deficiency – disrupts the normal functioning of the thyroid gland
Pituitary gland damage – The pituitary gland is a master gland that regulates the functioning of other endocrine glands in the body. If it is damaged, the regulation of the function of various glands, including the pituitary gland, is disrupted.

Timely diagnostics and treatment of hypothyroidism gives very good results in children.

Congenital hypothyroidism

Congenital hypothyroidism affects 1 in 4000 newborns. Newborns born with congenital hypothyroidism sometimes have an underdeveloped, absent, or abnormally positioned thyroid gland. In most cases, the thyroid gland of newborns born with congenital hypothyroidism is structurally normal, but its functional activity is impaired.

Congenital hypothyroidism can also be detected during routine newborn screening. Early diagnostics protects them from growth and development delays. If left untreated, children born with hypothyroidism develop delayed motor and mental skills: sitting, crawling, walking, speaking, perceiving, etc. If left untreated, congenital hypothyroidism causes decreased muscle tone, prolonged jaundice, feeding disorders, and more.

Symptoms of hypothyroidism in children

Decreased thyroid function causes a slowdown in a number of processes in the body, which manifests itself in the corresponding symptoms.

Height deficit compared to the age norm
Lack of energy and general weakness
Delayed puberty or irregular menstrual cycles in girls
Tendency to constipation
Weight gain
Muscle spasms
Dry skin and hair
Increased sensitivity to cold
Frozen limbs
Mood swings
Reluctance

Because the symptoms of hypothyroidism are general and can be related to other causes, laboratory tests are necessary to make a differential diagnostics.

Subclinical hypothyroidism

Subclinical hypothyroidism is a condition in which the thyroid-stimulating hormone (TSH) level is slightly above the upper limit of normal, but the levels of the thyroid hormones triiodothyronine (T3) and thyroxine (T4) are still within the normal range.

Subclinical hypothyroidism does not have pronounced symptoms and often hormone disorders are detected during routine tests. Subclinical hypothyroidism in children often heals on its own. If the doctor does not consider treatment necessary, it is recommended to monitor hormone levels every 6 months. If the TSH level gradually increases, it is necessary to start treatment.

In subclinical patients with elevated autoantibody concentrations, goiter, or elevated cholesterol levels, treatment should be initiated without delay.

Hypothyroidism treatment

Regardless of whether it is acquired or congenital, the treatment of hypothyroidism is the same – hormone replacement therapy with levothyroxine. During treatment, regular laboratory monitoring is necessary – to ensure that hormone levels and medication dosage are in line. Too high a dose of medication can lead to hyperthyroidism – a disease caused by an excess of thyroid hormone. Hyperthyroidism in children causes anxiety, sleep disturbances, impulsive behavior, and more.

Recommendation

In young children, TSH levels should be measured 4-8 weeks after starting hormone therapy or before any change in medication dosage.

In relatively older children, TSH and T4 thyroxine levels should be determined every 3-12 months, until puberty.

forecast

When the cause of hypothyroidism is Hashimoto's thyroiditis, the condition is permanent, regardless of treatment. Hypothyroidism that develops after surgical removal of the thyroid gland is also permanent.

Hypothyroidism caused by iodine deficiency or other causes is usually treatable.

Hashimoto's thyroiditis