Having a high level of thyroid stimulating hormone (TSH) in the blood and physical symptoms may mean that you have an underactive thyroid gland (hypothyroidism). A failing thyroid is unable to make enough T3 and T4, the active hormone, to keep organs healthy. The pituitary gland reacts to insufficient levels of T3 and T4 by pumping out more TSH to stimulate the thyroid, which is why high levels of TSH can signal thyroid failure. If hypothyroidism is not treated, the disease progresses with more severe symptoms. Children and teens have a different set of symptoms. Hypothyroidism is easily treated by a daily supplement of artificial thyroid hormone to restore normal function.
What Is a High TSH Level?
TSH stimulates the production of thyroid hormone, which is critical for regulating metabolism and maintaining healthy muscles and joints. Guidelines for what is considered a normal TSH range have changed over the years. In their 2003 guidelines, the American Association of Clinical Endocrinologists recommended decreasing the upper normal TSH level from 5.0 to 3.0, and suggested normal TSH ranges, with thyroid hormone treatment, should run between 0.3-3.0 (www.aace.com, March 2003). In some cases, even "normal" TSH levels around 2.5 do not rule out thyroid failure if the patient is also experiencing multiple symptoms of thyroid deficiency. An elevated TSH level by itself is not enough to diagnose hypothyroidism, but a combination of high TSH and physical symptoms may indicate hypothyroidism.
Early Symptoms of Hypothyroidism
When the thyroid gland is not producing enough thyroid hormone, the first symptoms may be signs of a slower metabolism such as increased cold sensitivity, unexpected weight gain and feeling sluggish or always tired. Women may notice heavier periods as an early symptom of hypothyroidism. Hair may become thin and brittle. Unusual muscle or joint pain may also signal low thyroid activity.
Late Symptoms of Hypothyroidism
If hypothyroidism is not treated, symptoms may progress to include nervous system problems such as losing the sense of smell or taste. Speech may become hoarse or slow. Skin may thicken and appear puffy on the face, hands and feet.
Hypothyroidism Symptoms in Children and Teens
One of the earliest symptoms that thyroid function is low in children is a yellowing of the skin and whites of the eyes, called jaundice. Other signs in infants might be recurrent choking episodes, a protruding tongue and general puffiness around the face. Some adult symptoms can also occur in infants as the disease progresses, including constipation, sluggishness and weak muscle tone. Hypothyroidism in a growing child, if left untreated, can stunt growth and cause mental retardation. Children and adults can be treated with oral thyroid hormone to supplement the low levels produced by the failing thyroid gland.
