Selling blood tests online for over 15 years.
We have processed over 3 million results.
Get secure and personalised results online.
A qualified clinician will interpret your results.
Everything you need to know about hypothyroidism
An underactive thyroid, also referred to as hypothyroidism, occurs when the gland does not produce enough of the thyroid hormones thyroxine (T4) and triiodothyronine (T3). Low thyroid hormone levels ultimately slow down the body’s metabolism.
Hashimoto’s disease which is an autoimmune disorder is the most common cause of hypothyroidism. In Hashimoto’s disease, the body’s immune system mistakenly identifies the thyroid as an invader with a foreign being in the body and produces antibodies that target and destroy the thyroid gland. Destruction of the gland eventually leads to a decrease in the levels of thyroid hormones produced. In the short term, some people experience a brief period of hyperthyroidism (over-active thyroid). Like many autoimmune diseases, women have an increased risk of developing Hashimoto’s disease compared to men.
Other causes of hypothyroidism include:
Hypothyroidism causes a decrease in metabolic rate which causes symptoms such as:
Often hypothyroidism symptoms can mimic other conditions, and because of this, hypothyroidism is often misdiagnosed. A blood test to measure thyroid hormone and antibody levels is the best way to diagnose hypothyroidism.
Symptoms that resemble hypothyroidism can be caused by a wide range of conditions so it is important to check for conditions such as diabetes, vitamin deficiencies (vitamins B12, D and folate) .and anaemia at the same time.
In the most common forms of hypothyroidism, it is the thyroid gland which is producing too little T3 and thyroxine. In these conditions, the pituitary gland is functioning normally so TSH production will be increased as the body is trying to drive up thyroxine and T3 levels. This gives the result below:
T3: Low or low normal
There are less common forms of hypothyroidism in which the pituitary gland malfunctions and produces too little TSH. So although the thyroid gland is healthy, it is understimulated by TSH and produces too little T3 and t4. This gives the result below:
T3: Low or low normal
There is no known way of preventing an underactive thyroid, but there are effective ways to treat and ease the symptoms. The most common treatment for hypothyroidism is the synthetic thyroid hormone levothyroxine, an oral medication capable of restoring thyroid hormone levels. Increasing hormone levels can reverse the signs and symptoms of hypothyroidism.