The thyroid gland is often described as something that looks rather like a butterfly. It is located in the front of your neck and wraps around your trachea or windpipe. Its job is to create chemical hormones which it releases into the bloodstream. These hormones act as messages and affect the cells and tissues in other parts of the body adjusting the body’s metabolic rate and controlling certain vitamin levels in your bloodstream. If you work in London and you need to have a thyroid function test, you can minimise the time you have to take off work by using the walk-in services of Broadgate Clinic London Wall.

What the thyroid gland does

The thyroid gland manufacturers 3 types of hormone; these are T3 (Triiodothyronine), T4 (Thyroxine), and CT (Calcitonin). The thyroid gland itself is managed by hormones produced in the brain; the hypothalamus and the pituitary gland. If the hypothalamus registers the fact that levels of T3 and T4 and/or the body’s metabolic rate is low, it will release a hormone that stimulates the pituitary gland to secrete TSH (Thyroid Stimulating Hormone). This then travels to the thyroid gland where it stimulates the gland into producing more T3 and T4 which is then released into the bloodstream in order to increase metabolic activity. Once the hypothalamus registers higher levels of T3, it stops sending out its chemical messages and the thyroid gland ceases its production of T3 and T4.

A malfunctioning thyroid gland

When the thyroid gland misbehaves, it creates a condition known either as hyperthyroidism (an overactive thyroid gland), or hypothyroidism (an underactive thyroid gland).

The symptoms of hyperthyroidism

An overactive thyroid gland (hyperthyroidism) produces too much T4 (Thyroxine). This causes your body’s metabolism to speed-up. Typical symptoms include:

  • Feeling restless, emotional, irritable, and/or nervous, and not being able to sleep properly
  • Trembling hands
  • Weight loss, in spite of having an increased appetite
  • Heart palpitations
  • Perspiring heavily with an increased thirst and an aversion to heat
  • Experiencing diarrhoea or passing stools more often
  • Shortness of breath
  • Thinning hair
  • Itchy skin
  • Changes in menstruation (becoming lighter or more infrequent)
  • Fatigue and muscle weakness
  • Swelling of the thyroid gland (Goitre)
  • Problems with eyesight (associated with Graves’ disease)

Not all of these symptoms are experienced by sufferers of hyperthyroidism, but several may present themselves at once. The longer the condition is in evidence, the higher the levels of Thyroxine will become, making the condition and the symptoms even more pronounced.

The symptoms of hypothyroidism

An underactive thyroid gland, (hypothyroidism), causes too little T4 (Thyroxine) to be produced. This leads to your body’s metabolism slowing down. Typical symptoms include:

  • Aches and pains
  • Constipation
  • Depression
  • Dry skin
  • Feeling cold
  • Fluid retention
  • Slowing of mental agility
  • Weight gain

As with hyperthyroidism, not all of the potential symptoms of hypothyroidism are experienced at once, and the longer the condition continues, the lower the bloodstream’s levels of Thyroxine will become and the more acute the symptoms.

Thyroid function blood test

Both hyperthyroidism and hypothyroidism are diagnosed by carrying out a blood test. This blood test is available from your GP, or, if you work in London, from Broadgate Clinic London Wall. The sample of blood taken is then be tested for either one or both of the substances T4 (Thyroxine) and/or TSH (Thyroid Stimulating Hormone).

A test revealing a low level of TSH indicates that your thyroid gland in overactive. This is further confirmed if your blood sample contains a high level of T4 hormone; the diagnosis being hyperthyroidism.

A test revealing a raised level of TSH indicates that your thyroid gland in underactive. This is further confirmed if your blood sample contains a low level of T4 hormone; the diagnosis being hypothyroidism.

Treating hyperthyroidism

The treatment prescribed for hyperthyroidism is a course of carbimazole. This is taken to reduce the amount of Thyroxine being produced by the thyroid gland. It takes anywhere from 4 to 8 weeks to take effect. The treatment is normally administered for between 12 and 18 months after which Thyroxine production levels settle down. If you are expecting or are breast feeding, an alternative medication called propylthiouracil will be prescribed. Both propylthiouracil and carbimazole can be prescribed by your GP, or, if you work in London, by the clinicians at Broadgate Clinic London Wall.

Treating hypothyroidism

The treatment prescribed for hypothyroidism is a course of levothyroxine tablets, one to be taken per day ideally before breakfast. This serves to replenish the levels of Thyroxine in your bloodstream. This treatment is successful in the majority of cases. In more severe cases a course of radioiodine may be prescribed. Both radioiodine and levothyroxine can be prescribed by your GP, or, if you work in London, by the clinicians at Broadgate Clinic London Wall.