nhsManagers.net | Briefing | 29 October 2017 Medicine for Managers Dr Paul Lambden BSc MB BS BDS FDSRCSEng MRCS LRCP DRCOG MHSM FRSM It produces thyroid hormones. There are two, thyroxine (or T4) and Tri- iodothyronine (or T3). It is one of the most important glands in the body because it controls metabolism. The hormones are secreted into the blood and the higher the level of the hormone the more rapidly the body’s processes operate. In general terms, someone with low thyroid function is slow in body and thought whilst the person with elevated thyroid activity is overactive mentally and physically. Controlling the thyroid In the healthy patient the thyroid is cleverly controlled. In simple terms, under normal circumstances, the thyroid produces thyroid hormone. It circulates in the blood including to the brain, through the hypothalamus (see diagram) The hypothalamus samples the blood and releases a hormone called Thyroid- Release Hormone (TRH) acts on the pituitary gland (see diagram) to produce Thyroid Stimulating Hormone which acts on the thyroid gland to adjust the thyroid hormone. Medicine for Managers articles are not intended to be a source of medical advice. Their purpose is to familiarise the non-medical reader about current key medical disorders. Any medical or medicinal products mentioned by name are examples only and should not be regarded as an endorsement of their use. That Clever Thyroid Gland The thyroid gland is found at the lower part of the front of the neck. It consists of two ovoid lobes connected by an isthmus and looks a bit like a bow tie. It weighs up to about an ounce and each lobe is about two inches by about two-thirds of an inch. It may be small but it exerts considerable control over the body.
Transcript
nhsManagers.net | Briefing | 29 October 2017
Medicine for Managers
Dr Paul Lambden BSc MB BS BDS FDSRCSEng MRCS LRCP DRCOG MHSM FRSM
It produces thyroid hormones. There are two, thyroxine (or T4) and Tri-iodothyronine (or T3).
It is one of the most important glands in the body because it controls metabolism. The hormones are secreted into the blood and the higher the level of the hormone the more rapidly the body’s processes operate.
In general terms, someone with low thyroid function is slow in body and thought whilst the person with elevated thyroid activity is overactive mentally and physically.
Controlling the thyroid
In the healthy patient the thyroid is cleverly controlled. In simple terms, under normal circumstances, the thyroid produces thyroid hormone.
It circulates in the blood including to the brain, through the hypothalamus (see diagram)
The hypothalamus samples the blood and releases a hormone called Thyroid-Release Hormone (TRH) acts on the pituitary gland (see diagram) to produce Thyroid Stimulating Hormone which acts on the thyroid gland to adjust the thyroid hormone.
Medicine for Managers articles are not intended to be a source of medical advice. Their purpose is to familiarise the non-medical reader about current key medical disorders. Any medical or medicinal products mentioned by name are examples only and should not be regarded as an endorsement of their use.
That Clever Thyroid Gland The thyroid gland is found at the lower part of the front of the neck. It consists of two ovoid lobes connected by an isthmus and looks a bit like a bow tie. It weighs up to about an ounce and each lobe is about two inches by about two-thirds of an inch. It may be small but it exerts considerable control over the body.
Therefore if thyroid hormone falls, the brain produces more TRH, which produces more TSH, which produces more thyroid hormone. If there is too much thyroid hormone, the brain produces less TRH, which produces less TSH, which tells the gland to produce less thyroid hormone.
This is called a negative feedback system.
Disorders of the thyroid
If the thyroid gland does not work properly, the result will be a set of symptoms depending on whether it produces too much or too little thyroid hormones.
Too much thyroid hormones results in hyperthyroidism (hyper meaning ‘over’) which increases the body’s metabolism resulting in a speeding up of the body’s physical and mental processes. This disorder is also referred to as thyrotoxicosis. It is accompanied by a set of recognisable symptoms which include:
• Palpitations • Increased heart rate with rapid
pulse • Nervousness and irritability • Aggression and moodiness • Warm, moist hands which display a
tremor • Weight loss • Increased appetite • Diarrhoea • Tiredness and lassitude • Eye problems which may be
teariness, sensitivity, irritation or grittiness. In more severe cases the eyes may protrude from the sockets.
The causes of hyperthyroidism include Grave’s disease, a toxic goitre, a thyroid adenoma or inflammation of the thyroid. Grave’s disease, named after Robert Graves who first described it, is one of a group of conditions called auto-immune diseases.
In this particular disorder, the reaction causes the thyroid gland to grow and produce more thyroid hormone. It is not fully understood but there is believed to be a genetic component and Grave’s disease tends to run in families.
Tissue nodules or more general overgrowth of thyroid tissue (toxic goitre or adenoma) will also result in the production of more thyroid hormone.
Too little thyroid hormones results in hypothyroidism (hypo- means ‘under’) and the body’s metabolism slows down resulting in a slowing of mental and physical processes.
The symptoms are broadly the opposite of those associated with hyperthyroidism and include:
• Slow pulse • Low mood and depression with
difficulty in concentration, slowness of thought and memory loss.
• Hoarse voice, slow speech • Dry coarse skin and hair loss
Medicine for Managers articles are not intended to be a source of medical advice. Their purpose is to familiarise the non-medical reader about current key medical disorders. Any medical or medicinal products mentioned by name are examples only and should not be regarded as an endorsement of their use.
• Increase in weight. • Facial puffiness • Muscle weakness, slow movements • Cramps • Infertility, loss of sex drive, heavy
periods • Raised blood pressure and high
cholesterol
The incidence of thyroid disease Hypo- and hyperthyroidism are about twelve times more common in women than in men and they each affect about one man in 1,000. About one in every 4,000 children is born with a congenital form of hypothyroidism and for that reason babies are tested using a blood spot when they are five days old.
The causes of hypothyroidism are auto-immune thyroid disease, as a consequence of treatment for hyperthyroidism, some medications and as a result of thyroid cancer or because of radiotherapy for its treatment.
In this auto-immune disease, the body produces antibodies which fail to recognise the body as ‘host’ but instead identify it as foreign and produce a tissue reaction which damages the capacity of the gland to produce thyroid hormones.
Some cases are the result of treatment to an over-active thyroid by surgery or radio-active iodine which leaves too little functioning thyroid tissue and converts the patient from hyperthyroid to hypothyroid.
Diagnosis of thyroid disease
The diagnosis of both conditions is commonly strongly suspected by a general physical examination. It can be confirmed
by blood test measurement of the thyroid hormones. The blood tests will include measurement of thyroid antibodies to establish whether the cause is auto-immune.
The measurement of the thyroid stimulating hormone (TSH) level will also assist in confirming the diagnosis.
Further testing will depend on the nature of the disorder and the suspected diagnosis. It may involve an ultrasound scan, MRI scan, specialised radiology using a radio-active marker or a biopsy.
Treatment of thyroid disease
Benign thyroid disease is usually treatable according to whether too much or too little hormone is being produced. In cases of hyperthyroidism, control may be achieved by:
• The use of medication (anti-thyroid drugs) to curtail the production of thyroid hormone by the thyroid gland
• The use of radio-active iodine to destroy a proportion of the thyroid hormone producing cells in the gland.
• Surgery to remove part or all of the gland
In hypothyroidism, the consequences of inadequate thyroid hormone involve taking a thyroid replacement called levothyroxine to replace the hormone.
It is given by tablet because the hormone is not destroyed by stomach acid. It normally enables the patient to enjoy a healthy life.
Medicine for Managers articles are not intended to be a source of medical advice. Their purpose is to familiarise the non-medical reader about current key medical disorders. Any medical or medicinal products mentioned by name are examples only and should not be regarded as an endorsement of their use.
In cases of cancer of the thyroid, the treatment is by surgery, chemotherapy or radiotherapy according to the most effective therapy for the particular tumour.
If I may be permitted a small observation on the UK-European relationship, I would remind you that most hyperthyroidism is due to Grave’s disease.
It was described by Robert Graves in Ireland in 1835. It was also described by Karl von Basedow in Germany in 1840.
Today, the condition is still known as Grave’s disease in the English-speaking world but as Basedow’s disease in most of Europe!
In fact, Guiseppe Flajina and Antonio Testa had written about it in 1902 and 1810 respectively.
Occasionally, in Europe, it is still known as Flajina-Basedow disease.
Medicine for Managers articles are not intended to be a source of medical advice. Their purpose is to familiarise the non-medical reader about current key medical disorders. Any medical or medicinal products mentioned by name are examples only and should not be regarded as an endorsement of their use.
