Low thyroid by Ray Sahelian, M.D.
Low Thyroid is a
condition in which the thyroid gland does not produce enough thyroid hormone,
which regulates the way the body uses energy. The medical name for low thyroid
is hypothyroidism. Low thyroid usually develops slowly. It often results from a
problem in which the body's own natural defense (immune) system attacks the
thyroid gland (autoimmune thyroiditis or Hashimoto's thyroiditis). Low thyroid
may also develop following radiation treatment or surgical removal of the
thyroid.
Low thyroid symptom
A low thyroid level can cause symptoms of fatigue, weakness, lethargy, weight
gain, depression, memory problems, constipation, dry skin, intolerance to cold,
brittle nails, or a yellowish tint to the skin. Another common side effect of
low thyroid is coarse or thinning hair.
Low Thyroid Treatment
Low thyroid is treated with medications to replace the thyroid hormone. Low
thyroid symptoms usually disappear within a few months after treatment begins,
but most people need to continue taking thyroid hormones for life.
Low thyroid function without symptoms increases heart risk
Older adults who have low thyroid, or hypothyroidism, but with no
symptoms, have an increased the risk of congestive heart failure, but not other
cardiovascular disease or death.
Asymptomatic hypothyroidism is characterized by an increased level of thyroid
stimulating hormone (TSH), but a normal level of thyroxine (T4). The prevalence
of this condition increases with age.
Asymptomatic low thyroid has been associated with higher levels of some cardiac
risk factors. Congestive heart failure is more common in patients with moderate or severe asymptomatic
low thyroid. Moderate asymptomatic low thyroid is defined as a TSH level of
7.0 to 9.9 mIU/L and severe asymptomatic low thyroid as a TSH of 10 mIU/L or
greater. Older
adults with TSH levels of 7.0 mIU/L or higher had a two fold increased risk of
congestive heart failure.
Heart failure is not increased among those with TSH levels between 4.5 and 6.9
mIU/L, which indicates mild asymptomatic low thyroid. Archives of Internal Medicine, November 28, 2005.