Hypothyroidism is a common disorder associated with thyroid hormone deficiency. The thyroid gland is one of the largest components of the endocrine system. It is located in the neck, right below the voice box or larynx. Its main function is to produce two primary thyroid hormones as T3 or triiodothyronine and T4 or thyroxine. These hormones are to facilitate regulation of the body’s metabolism, energy consumption, brain development, protein production, and hormone sensitivity. There are many harmful effects associated with hypothyroidism and they only worsen over time. Therefore, it is important to know of its presence early on. By monitoring subclinical hypothyroidism, not to be confused with subclinical hyperthyroidism, it is possible to avoid the worst of this disease.
Symptoms of Hypothyroidism
Before discussing subclinical hypothyroidism, it is important to under the many harmful symptoms in hypothyroidism. These include:
- inability to withstand cold temperatures
- increased pain in joints and muscles
- weight gain
- slowed heart rate
- skin dryness
- decreased sweating
- memory problems, depression, or problems concentrating
- yellowish skin
- slow body movement
If allowed to develop further, hypothyroidism could become lethal. A condition known as myxedema coma may occur, which causes its own host of life threatening symptoms:
- Mental deterioration
- Extremely low body temperature (hypothermia)
- Extremely slow heartbeat
- Heart failure
- Respiratory failure
What is Subclinical Hyperthyroidism?
Subclinical Hyperthyroidism differs from subclinical hypothyroidism in that the former is defined by mild over activity of thyroid hormone production. This condition is defined by low levels of thyroid stimulating hormones (TSH) and normal levels of thyroxine (T4) and triiodothyronine (T3). It is different from normal hyperthyroidism in that TSH levels are low but thyroid hormone levels are normal. Some symptoms may include loose of weight and anxiety. As always, one should consult a doctor for proper diagnosis.
Causes of Subclinical Hypothyroidism
Like most cases of hypothyroidism, a chief cause of it comes from Hashimoto’s Thyroiditis. This is characterized by the immune system attacking the thyroid gland, thereby limiting hormone production. This is no different in subclinical hypothyroidism, which is simply a milder, earlier version of hypothyroidism. This form of hypothyroidism has the potential to develop into a more serious condition given time. Many of the causes for hypothyroidism apply here as well:
- Surgery to remove the thyroid gland
- Radiation therapy for cancer
- Viral infections
- Some drugs, such as lithium
- Parents who either have autosomal dominant (meaning they have hypothyroidism) or autosomal recessive (they do not have the disease, but are carriers for it) could easily pass hypothyroidism down to their children
- Having too much iodine may actually trigger thyroid disease despite the fact it is an element mean to make thyroid hormones. This could cause the hormone production to become over active
- Unhealthy levels of radiation can increase cases of thyroid disease. Incidents such as the nuclear bombing of Nagasaki and Hiroshima and the nuclear meltdown in Chernobyl can all cause radiation poisoning as well as create a breeding ground for hypothyroidism
Symptoms of Subclinical Hypothyroidism
In hypothyroidism, the symptoms are defined by the effects of the lack of hormone production. This causes many of the functions in the body to either slow down or weaken over a long period of time. This is no different in subclinical hypothyroidism, albeit at a much milder stage:
- cold intolerance
- weight gain
- memory problems
- joint and muscle pain
- skin dryness
- loss of hair
Just like normal hypothyroidism, subclinical effects up to 20% of women over the age of 60 and about 2% to 5% of people with subclinical disease develop hypothyroidism every year.
Treatment for Subclinical Hypothyroidism
Detecting signs of hypothyroidism early on is an important factor in treating the disease. Diagnosis of the disease is based on various measurements of hormone levels. By measuring levels Thyroid Stimulating Hormones or TSH as well as thyroxine or T4, a professional is able to determine the severity of the disease. A somewhat high level of thyroid-stimulating hormone level and a slightly low thyroxine level mean there are signs of subclinical hypothyroidism.
One form of treatment includes the use of the synthetic thyroid hormone known as L-thyroxine. Administered in small doses, this can replace lost hormones (source).