Thyroid hormone problems can happen in both low production called hypothyroidism or high production called hyperthyroidism. Thyroid hormones need to be produced in adequate amounts for proper functioning of the body and both low or high can be problematic.
Hypothyroidism is a common endocrine disorder in which your child's thyroid gland does not produce enough thyroid hormone. A child with an underactive thyroid may experience fatigue, weight gain, constipation, decreased growth, and a host of other issues. Your child’s thyroid is a small, butterfly-shaped gland in the front of the neck, just below the thyroid cartilage (Adam’s apple). Hormones produced by the thyroid affect all aspects of your child’s health including heart rate, energy metabolism (how effectively the body uses calories), growth and development.
Hyperthyroidism (overactive thyroid) is a condition in which your child’s thyroid gland makes too much thyroid hormone. The over-secretion of thyroid hormone leads to over-activity of your child’s metabolism and can cause weight loss, a rapid or irregular heartbeat, sweating, nervousness, irritability, anxiety and decreased school performance.
Treatment for hyperthyroidism depends on the severity of your child’s condition. Most children are helped with anti-thyroid medications. Another treatment option is radioactive iodine to slow the production of thyroid hormone. In some cases, surgery to remove part or all of your child’s thyroid gland is necessary.
Signs and symptoms of hypothyroidism
Symptoms of hypothyroidism are usually subtle and gradual, and may resemble those of other conditions or medical problems. Many symptoms are non-specific and may be ignored as normal parts of our everyday lives. Because of this, the condition may go undetected for years.
- Fatigue and/or exercise intolerance
- Slower reaction time (an important issue for drivers)
- Weight gain
- Constipation
- Sparse, coarse and dry hair
- Coarse, dry and thickened skin
- Slow pulse
- Cold intolerance
- Muscle cramps
- Sides of eyebrows thin or fall out
- Dull facial expression
- Hoarse voice
- Slow speech
- Droopy eyelids
- Puffy and swollen face
- Enlarged thyroid, producing a goiter-like growth on the neck
- Increased menstrual flow and cramping in girls and young women
Signs and symptoms of hyperthyroidism
Symptoms of hyperthyroidism may be mild or severe. In some cases, the severity of symptoms is not related to the level of thyroid hormone. Some children may have significant complaints with slightly elevated thyroid hormone levels, while others may report fewer symptoms with extremely elevated thyroid hormone levels.
- Enlarged thyroid (called a goiter)
- Increased heart rate or feeling the heart is "racing"
- Increased blood pressure
- Slight tremor
- Lighter and less frequent menstrual cycle for teens and young women
- Irritated and/or bulging eyes with redness or visible blood vessels on the white part of the eye, pain when moving the eyes, and inability to fully open the eye lid (Graves’ ophthalmopathy)
- Mood changes such as anxiety, irritability and nervousness
- Increased activity, fidgetiness, hyperactivity, restlessness
- Poor, restless sleep
- Fatigue
- Increased appetite — with or without weight loss
- Increased number of bowel movements per day
- Heat intolerance (always feeling warm)
- Decreased or poor school performance
- Difficulty concentrating; may be diagnosed with "late-onset" attention deficit disorder
- Feeling of a “lump” in the throat
Testing and diagnosis
Diagnostic evaluation begins with a thorough medical history and physical examination of your child. The most common cause of congenital hypothyroidism is that the thyroid gland did not move to the correct location in the lower third of the neck during prenatal development.
- Thyroid function screening, a blood test that measures thyroid hormone (thyroxine or T4) and serum TSH (thyroid-stimulating hormone) levels. Hypothyroidism is diagnosed when the TSH levels are above normal and T4 levels are below normal. A less severe or earlier form of hypothyroidism is reflected by an elevated TSH and a low-normal T4, a condition called "compensated" or "subclinical" hypothyroidism.
- Anti-thyroid antibody level studies. Anti-thyroperoxidase (anti-TPO) and anti-thyroglobulin (TgAb) are elevated in autoimmune hypothyroidism. In contrast to the antibody found in Graves' disease (a type of hyperthyroidism), these have no function. They only serve as a indicator of the diagnosis.
- Thyroid ultrasound, which uses ultrasonic waves to image your child's thyroid and lymph nodes. An ultrasound does not expose your child to radiation. In some forms of hypothyroidism, the thyroid tissue will have an irregular appearance and there may be areas that look like a thyroid nodule. Expert review of the images by an experienced pediatric endocrinologist will determine if the area warrants further investigation with fine needle aspiration (FNA) or if it can be followed with repeat thyroid ultrasound to determine if FNA is needed. Ultrasound can also be used to ensure a newborn with congenital hypothyroidism has a normal thyroid in the correct location.
- Nuclear medicine uptake and scan, which helps determine how well your child’s thyroid tissue absorbs iodine, a key ingredient in making thyroid hormone. For the test, your child is given a very small amount of radioactive iodine — usually technetium 99m (TC-99m) or I-123 — then we measure how much iodine is absorbed (uptake) and the pattern of distribution of the radioiodine in the thyroid tissue (scan). This test can also be used to determine the location of thyroid tissue for newborns with congenital hypothyroidism.
