Hypothyroidism

Hypothyroidism means the body doesn’t make enough thyroid hormone for normal growth, bone development, and to control how the body uses energy to work (metabolism). When the metabolism slows, many body functions slow down.

An underactive thyroid can be caused by a cyst, surgery, radiation, medicine, injury to the thyroid gland, problems with the pituitary gland, or an autoimmune condition. When the body mistakenly attacks itself and damages the thyroid, it is an autoimmune disorder called Hashimoto’s disease.

The Thyroid Gland

The thyroid is a gland in the bottom of the inside of the neck. It is shaped like a butterfly (Picture 1). It makes 2 important hormones called triiodothyronine (T3) and thyroxine (T4). The pituitary gland makes another important hormone in the brain called thyroid-stimulating hormone (TSH). TSH tells the thyroid gland to make T3 and T4.

Together, these hormones help control the amount the body needs for:

• Metabolism
• Brain and body growth and development.
• Heart, liver, and kidney function.

Congenital Hypothyroidism

Congenital hypothyroidism means you were born with an underactive thyroid.

All newborns are tested for hypothyroidism shortly after birth. Treatment must be started in the first weeks of life to prevent permanent harm to the brain and learning problems.

There are 2 types of congenital hypothyroidism:

• Transient hypothyroidism – Abnormal thyroid hormone levels caused by thyroid medicine taken during pregnancy or when the pregnant parent’s body mistakenly attacks the baby’s thyroid. Transient hypothyroidism usually goes away and doesn’t need long-term treatment.
• Permanent hypothyroidism – Due to abnormal growth of the thyroid, like being too small, absent, or in the wrong place.

Your child’s doctor or health care provider may not know if their congenital hypothyroidism is permanent or transient until they’re 2 to 3 years old.

Symptoms

Your child may or may not have symptoms. Symptoms of hypothyroidism in children are different from those in adults. Older children and teenagers may have the same symptoms. The most common symptoms are:

• Newborns: Yellow color of the skin or eyes (jaundice) and poor feeding.
• Children: Weight gain, not getting taller (slowed linear growth), problems concentrating, sleepiness, fatigue, sensitivity to cold, decreased heart rate, and constipation.
• Teenagers: The same symptoms as in children, plus delayed puberty and irregular menstrual cycles.

Diagnosis

Your child may have:

• Blood tests to measure the level of hormones in the thyroid and pituitary glands.
• An ultrasound that uses sound to create pictures of the thyroid gland.
• X-rays to see bone growth.

Treatment

The treatment of hypothyroidism is simple, safe, and effective. Your child will take one pill each morning to replace the missing thyroid hormone.

When to See the Doctor

• Your child will see a doctor or health care provider regularly. At first, it may be every 3 to 4 months. As they get older and their hypothyroidism is controlled, they will visit every 6 to 12 months.
• With the right treatment and the correct dose of medicine, your child’s chances for normal growth and development are good.

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