Although hypothyroidism is most common in adults, it can occur in children and adolescents as well. It's difficult to recognize the symptoms of underactive thyroid in children because signs that are characteristic for the disorder such as changes in sleeping habits, appetite, and the levels of a child's energy can be a normal part of growing up. Underactive thyroid disorder is a lot more common in children than overactive thyroid or hyperthyroidism.
Infants can get hypothyroidism too, and it's usually discovered on regular screening tests. If we speak about the condition that the baby is born with, it's called congenital hypothyroidism. Routine screenings as soon as a baby is born have shown that one in every 1,500 to 3,000 babies is born with the underactive thyroid gland.
If someone in the family has hypothyroidism or any autoimmune disorder, a newborn is at risk as well. After the condition is treated in infancy, testing isn't usually done anymore unless parents or a child's pediatrician specifically ask for testing.
There are a few autoimmune disorders that may cause underactive thyroid such as Type 1 diabetes, Hashimoto's disease, as well as Graves' disease. There are a few more reasons why children might get hypothyroidism:
- Lack of iodine in the diet
- Pituitary gland disorder
- Lack of treatment for the mother's underactive thyroid while pregnant
Symptoms of underactive thyroid in babies
Signs of underactive thyroid often appear soon after the baby is born, but they can be easy to miss as they tend to be quite subtle at the beginning. The levels of thyroid hormone in babies are just a little under normal, which makes this symptom easy to miss. As the child grows, they become more and more apparent and often include:
- Jaundice – If a child has an underactive thyroid, it reduces the rate of bilirubin conjugation and affects appetite, which leads to jaundice.
- Decreased appetite – Child refusing to feed is one of the common signs of an underactive thyroid.
- Big fontanel – The size of a soft spot on a baby's head is 2.1 cm on average. In babies with hypothyroidism, it's usually larger and takes longer to close. In fact, an underactive thyroid is a common reason for increased fontanel.
- Decreased activity – Babes with underactive thyroid tend to seep more and are more lethargic than the average child.
- Protruding navel – Infants with underactive thyroid often have a condition called umbilical hernia, where the navel sticks out.
- Swollen tongue – Underactive thyroid in children is often accompanied by macroglossia. This condition is characterized by big, thick lips, a large tongue, and late teeth eruption.
Common symptoms of underactive thyroid in bigger children
If hypothyroidism isn't detected until the age of three when most brain development that requires good levels of thyroid hormone is done, the signs of hypothyroidism might be tricky to detect but may cause a lot of issues such as:
- Compromised growth – Underactive thyroid may lead to poor growth, not only regarding the height, but regarding limb length as well if the condition is not diagnosed on time.
- Facial swelling – Hypothyroidism can cause myxedemia, a condition characterized by puffy face, lips, and limbs. This is because mucopolysaccharides are accumulated in the dermis.
- A goiter – When a thyroid gland increases in size, it's a definite sign of thyroid problems, but it's not specific which disease, as it can mean hyperthyroidism, as well as hypothyroidism.
- Delayed tooth eruption – The same as with infants, hypothyroidism can cause delayed tooth growth in school children with underactive thyroid too.
- Premature puberty – hypothyroidism may cause puberty to hit sooner (also a lot later) than expected, depending on a child and the severity of the condition.
- Delayed cognitive development – If a child suffers from hypothyroidism, it can lead to mental disability and cognitive delays, especially in school children if left untreated.
- Slow heart rate – Also known as bradycardia, this is a common symptom of hypothyroidism in toddlers and school kids.
Children can have the same symptoms of underactive thyroid as adults including constipation, cold skin, as well as fatigue, but unlike adults, childhood hypothyroidism never leads to weight gain.
Symptoms of underactive thyroid in teenagers
Teens get hypothyroidism mostly due to some autoimmune disorder or a genetic disorder like Down syndrome and signs and symptoms don't differ much from adults' symptoms including:
- Feeling constipated
- Having dry skin and brittle nails
- Rough voice
- Puffy face
- Increased thyroid gland
- Pain in joints and muscles
These symptoms can be attributed to many things and are often hard to recognize. Teens with underactive thyroid can also go through physical symptoms such as:
- Increase in body weight – Even though infants and school kids never experience weight gain as a result of underactive thyroid, it's a common sign of hypothyroidism in teenagers.
- Delayed puberty – Hypothyroidism an cause children to go through puberty sooner, but also a lot later than expected. When it comes to underactive thyroid and teens, it especially affects girls. It can prolong menstrual bleeding, and also delay the time of the first period. It tends to slow down breast growth. In boys, underactive thyroid can cause testicles to increase in size.
- Mood changes – Teens with underactive thyroid tend to be tired and forgetful, have mood and concentrations problems, and often feel depressed.