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|Quick reference medical handouts used
by Pediatric offices
Hypothroidism in Children
Hypothyroidism is the condition in which
the thyroid is underactive and is producing an insufficient amount of
thyroid hormones. Hypothyroidism is the most common thyroid disorder.
However, children with the disorder display different symptoms from
- Infants and small children affected by hypothyroidism may have
significant problems with growth and development if it not diagnosed
and treated promptly.
- In older children and young adults, hypothyroidism can cause
diverse symptoms due to lack of thyroid hormone, including slowed
heart rate, chronic tiredness, inability to tolerate cold, mental
fatigue and difficulty in learning, and constipation.
Hypothyroidism can develop at any point in the lifespan. Infants can
be born with hypothyroidism, and hypothyroidism can develop in children
and adults of any age.
||The thyroid is a
butterfly-shaped gland located at the base of the neck, just
below thr Adam's apple. Although it weighs less than an ounce,
the thyroid gland has an enormous effect on your child's health.
All aspects of a child's metabolism, are regulated
by thyroid hormones.
The thyroid gland secretes thyroid hormones, which control
the speed at which the body's chemical functions proceed
(metabolism). To produce thyroid hormones, the thyroid gland
needs iodine, an element contained in many foods.
The thyroid gland also produces a hormone called
calcitonin, which may be involved in the metabolism
Normal levels of thyroid hormone are
vital for proper growth and development.Consequently, hypothyroidism, especially
in infants and young children, can lead to serious, sometimes permanent,
developmental problems if not detected and treated promptly.
For infants born with hypothyroidism,
diagnosis and treatment within the first month or so of life may prevent
any irreversible problems with the child's development. On the other hand, if diagnosis or
treatment is delayed until after the first two or three months of life,
permanent problems with the child's development, most noticeably mental
retardation, may be unavoidable.
The older the child when hypothyroidism
develops, the less the chances of permanent effects on the child.
Consequently, older children who develop hypothyroidism may show many of
the symptoms associated with inadequate organ stimulation (such as
slowed heart rate, difficulties in thinking and learning, and
constipation) but little, if any, permanent abnormality in growth or
Symptoms of hypothyroidism In Infants And Young Children
Hypothyroidism that occurs in infancy or early childhood is called
cretinism. Babies born with hypothyroidism classically show a number of
symptoms in the first weeks to months of life. At birth, many symptoms
are subtle, though, and can be missed. They include the following:
Over time, if untreated, other symptoms typically become apparent in
older infants, toddlers, and young children. The most obvious symptoms
observed in these youngsters reflect insufficient thyroid
hormone for growth and development:
- Puffy face, swollen tongue
- Hoarse cry
Cold extremities, mottled skin
- Low muscle tone (floppy, no strength)
- Poor feeding
- Thick coarse hair that goes low on
- Larger-than-normal soft spots on the skull
- Prolonged newborn jaundice (a yellow discoloration of the skin and
the whites of the eyes)
- Lethargic (lack of energy, sleeps most of
the time, appears tired even when awake)
- Persistent constipation, bloated or full
to the touch
- :Little to no growth
- Short stature for age and delayed eruption of baby teeth
- Delays in major developmental milestones
- Puffy facial features
- Severe mental retardation
- Protruding abdomen and umbilical hernia (a soft protrusion around
- Dry skin and sparse hair
Symptoms In Older Children
When hypothyroidism develops in older children before growth and
development are complete, they may have a shorter-than-average height or
may be delayed. They also may have symptoms that are more like those
found in adults:
Slow heart rate
Inability to tolerate cold
Dry, flaky skin
Puffiness in the face, especially around the eyes
Impaired memory and difficulty in thinking (which may appear as a
new learning disability)
Drowsiness, even after sleeping through the night
Heavy or irregular menstrual periods (in girls at the age of
- TSH - Thyroid
Stimulating Hormone is released by the pituary gland that
causes the thyroid gland to produce thyroid hormone
- T4 - a hormone secreted
by the thyroid gland which regulates metabolism.
- T3 - a hormone secreted
by the thyroid gland which regulates metabolism; exerts the
same biological effects as T4, but is generally more potent
and the onset of its effect is more rapid.
In the United States, Canada, and much of
the Western world, newborns are routinely screened for thyroid hormone
deficiency. Infants with abnormal screening tests receive follow-up
evaluation for hypothyroidism. Such testing commonly leads to the
correct diagnosis within the first four weeks of age, and treatment can
Diagnosis later in childhood is usually
based on information from blood tests, which check levels of thyroid
hormones T4, T3, and TSH, among other related substances. Abnormally low
levels of T4 and T3 indicate hypothyroidism is present.
- If TSH is present at a
higher-than-normal level, the abnormality is within the thyroid
It is not responding properly to TSH.
- If TSH is low, the abnormality is
within the brain or pituitary gland.
The pituitary is not releasing TSH despite levels of thyroid hormone
low enough that it should do so
Among babies with hypothyroidism, roughly
95% or more of cases represent problems in the thyroid gland. In less
than 5% of cases, the abnormality is found in the brain or in the
pituitary gland, the small gland at the base of the brain, almost always
the pituitary gland.
This is the same for hypothyroidism that
develops in older children and young adults, although the exact causes
of hypothyroidism are different for the different age groups.
Causes Of Hypothyroidism In Newborns
Hypothyroidism present from birth is called congenital hypothyroidism.
In North America, CH is found in roughly 1 in every 4,000 newborns. Congenital
used to be a major cause of mental retardation. Development of the
brain, as well as normal growth of the child, is dependent upon normal
levels of thyroid hormone.
hypothyroidism results in permanent hypothyroidism and require
life-long treatment, and these account for about 90% of all newborns
- Abnormal thyroid gland development includes babies born
without a thyroid gland and those whose thyroid is not functioning
(roughly 80% to 85% of cases).
- Abnormal thyroid hormone production is much less common
(roughly 10% to 15% of cases). It is often inherited.
- Abnormal development of the brain or pituitary gland is the
least common cause of permanent CH (fewer than 5% of cases).
Causes Of Hypothyroidism That Develops During
Hypothyroidism that develops during childhood has a number of causes.
In general, the older the child, the more likely it is that the cause
will be similar to the causes of hypothyroidism in adults.
Causes of hypothyroidism that develops during childhood include:
- Late appearance of a congenital problem - A congenital
problem is a problem with which a baby is born. But sometimes these
problems may only become apparent later, after the newborn period.
These children may have small or poorly formed thyroid glands that
could not meet the demands of the growing child.
- Inhibition of thyroid hormone production in the thyroid gland- Inability
to produce enough thyroid hormone may reflect poor function of an
apparently normal thyroid gland. This can be caused by too little iodine
in the diet or a drug taken for a non-thyroid condition inhibits the
production of thyroid hormone.
- Permanent thyroid cell loss as a consequence of a medical
treatment Autoimmune disease -
- Autoimmune disorders are the most
common cause of thyroid problems- in these conditions, the
normal ummune system mistakenly directs an immune "attack"
against is own healthy cells. Specifically, the immune system makes antibodies (or attack proteins)
that can affect the function of the thyroid. In Hashimoto's
the antibodies directly attack and destroy thyroid cells.
What Is The Treatment For Hypothyroidism?
No matter what form of hypothyroidism a child develops, the treatment
is always the same. It involves prescription thyroid replacement hormone
treatment, in pill form, This will supply the body with the
thyroid hormone that isn't being produced and released by the thyroid
gland. Synthetic (artificially produced) thyroid hormone (T4) is
manufactured in a wide range of strengths so that dosage can be
individually tailored for each child.
It is important that an experienced physician oversee treatment,
because the body's need for thyroid hormone varies over the course of
childhood and puberty. A child will usually be started on a daily dose
of thyroid hormone, have it adjusted until a healthy level of hormone in
the blood is reached, and then be monitored with regular blood tests.
Almost all children with hypothyroidism will require thyroid
hormone replacement therapy for the rest of their lives.
As a reminder, this information should not be relied on as
medical advice and is not intended to replace the advice of your childs pediatrician.
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