The NHS defines an underactive thyroid (or hypothyroidism) as a failure of the thyroid gland, located in the neck in front of the windpipe, to produce sufficient quantities of the hormones needed to regulate the body’s metabolism, such as triiodothyronine and thyroxine.
Without the right level of these hormones in production to moderate how the body stores and uses energy, many of its functions can gradually begin to slow down, affecting the internal organs.
Symptoms associated with hypothyroidism develop slowly and are often difficult to distinguish from other ailments with which they might also be associated.
The seven most common symptoms, according to Live Science, include creeping weight gain, fatigue, hypersensitivity to cold temperatures, muscle and joint aches, dry skin or thinning hair, heavy or irregular menstrual periods and depression.
Should you experience any of the above complaints, you should seek an appointment with your GP, who will carry out a thyroid function test, in which a sample of your blood is tested to measure the body’s hormone levels.
They will then typically prescribe a course of daily hormone replacement tablets, called levothyroxine, to raise your thyroxine levels.
Regular blood tests will be required to ensure your hormone levels have returned to the correct level thereafter, with an annual checkup advised once a satisfactory result has been achieved.
Without treatment, an underactive thyroid can lead to heart disease, goitre, pregnancy problems and, in rare cases, a life-threatening condition known as myxoedema coma, which is when hormone levels fall very low.
According to the health service: “There’s no way of preventing an underactive thyroid.
“Most cases are caused either by the immune system attacking the thyroid gland and damaging it, or by damage to the thyroid that occurs during some treatments for an overactive thyroid or thyroid cancer.”
While hypothyroidism can be experienced by both men and women, it is slightly more common in the latter.
Children can also suffer from it, with babies usually tested for congenital thyroid problems by blood test five days after being born.
For more information on the condition, visit the website of the British Thyroid Foundation.
