Thyroid Flashcards
what does endocrinology include
Disorders of hormones and the glands
What is the term steroids often used to describe
Anti-inflammatory and immunosuppressive drugs act via cortisol receptors
What are the 3 basic things that can go wrong with an endocrine gland
- Failure to produce its hormone
- Excessive production of hormone
- Swellings
What is a common cause of endocrine gland failure
Destruction of the gland
Give some examples of what may cause endocrine gland failure
1, Infection
2. Radiation
3. Invasion by tumours
4. Pituitary disease
5. Secondary to unregulated pituitary hormone secretion
6. Tumours
Give examples of adrenal gland disorders
- Cushing’s disease
- Addison’s disease
- Conn’ syndrome
What is Cushing’s disease caused by
An excess glucocorticoid production secondary to adrenal hyperplasia.
What effect does systemic steroid treatment suppress
Normal pituitary adrenal axis resultan in atrophy of the norm cortisol secretion adrenal cells
What can cortisol cause
Resistance to insulin resulting in impaired glucose tolerance or diabetes
What test should we do to assess and diagnose non iatrogenic bushings disease
measurement of the plasma or urine cortisol level, which will be elevated, and is not suppressed by dexamethasone
What can measurement of plasma ACTH help to distinguish
Pituitary cases from adrenal casues
Pituitary causes= raised ACTH
Adrenal causes= suppressed ACTH
What is Addisons disease
A non specific disease with general tiredness, weakness and weight loss
What is a key clinical clue indicating Addisons disease
hyperpigmentation generally seen over the whole skin but particularly prominent in the palmar creases of the hands, and on the buccal mucosa
If we don’t manage Addisons disease what can happen
Can become Addisons crisis
What are some feature of Addisons crisis
- Vomitting
- Loss of salt and water resultign in hypotension or hypoglycaemia
- May result in coma
How do we investigate for Addisons disease
Plasma cortical levels= will be low
ACTH may be raised
Adrenal autoantibodies
Real electrolytes and glucose also measured
How is Addisons crisis managed
Intravenous hydrocortisone, glucose, and fluid and electrolyte replacement
How is Addisons disease managed
hydrocortisone (cortisol) and fludrocortisone (aldosterone)
What does aldosterone do
Stimulates retention of salt and loss of potassium via the kidneys
In whom does conns syndrome occur in
People with a tumour or hyperplasia of the adrenal cortex resulting in high levels of aldosterone secretion
What can high levels of aldosterone lead to
Potassium loss and sodium retention
What can potassium loss lead to
Muscle weakness and polyuria
What can sodium retention lead to
Hypertension
What diseases/ disorders can the thyroid gland suffer from
- Hyperthyroidism
- Hypothyroidism
What does the thyroid gland do
Secreted iodine containing hormones thyroxine and triiodothyronine
What is overproduction of the thyroid hormone also known as
Hyperthyroidism or thyrotoxicosis
Give an example of hyperthyroidism
Graves Disease
What is Graves disease caused by
An antibody that binds to the thyroid stimulating hormone (TSH) receptor on the thyroid cells and stimulates it
Give some causes of hyperthyroidism
- Thyroid adenoma
- Toxic multi nodular goitre
- Graves disease
What does goitre mean
applies to a swelling of the thyroid gland
What are some symptoms of hyperthyroidism
- Weight loss
- Dislike of heat
- Tremor
- Irritability
- Emotionally labile
What are some signs of hyperthyroidism
- Tachycardia
- Atrial fibrillation
- Tremor
- Enlarged thyroid
- Exophthalmos Goitreo
What is the treatment for hyperthyroidism
- Carbimazole
- Partial thyroidectomy
- Radioactive iodine
Why do patients with hyperthyroidism lose weight without trying
Due to increased metabolic rate
Where might a patent with hyperthyroidism present with a goitre
front of the larynx in the neck which might move upwards on swallowing can be lumpy or smooth
Give some signs and symptoms of graves disease
- Smooth goitre
- Protrusion of the eyes (exophthalmos)
- Double vision
- Thyroid acropachy (fingernail clubbing)
- Thickening of the shins and dorsum of the foot
How can hyperthyroidism be investigated
Measurement of free plasma of t4 and t3 = will be raised
Thyroid secretion hormone will be suppressed
What is hypothyroidism
Severely underactive thyroid
What is a key characteristic of hypothyroidism
Deposition of mucinous material in the subcutaneous tissues - MYXOEDEMA
Describe the blood biochemistry of a patient with hypothyroidism
Low levels of T4 and T3
High thyroid secretion hormone
What can hypothyroidism be caused by
- Spontaneous due to primary autoimmune disease
- Drug induced eg antithyroid drugs
- Iodine deficiency
- radioiodine therapy or surgery to the thyroid gland
What are the symptoms of hypothyroidism
- Weight gain
- Dislike of cold
- lethargy
- Depression
- Puffy features eg bags under the eyes
- Deep and croaky voice
What are some of signs of hypothyroidism
- Bradycardia
- Goitre
- Dry skin and hair
How id hypothyroidism managed
Thyroxine replacement
What can hypothyroidism drugs be classified into
- Antithyroid drugs
- Iodide
- Radioactive iodine.
Other than thyroxine drugs what else might a person with hypothyroidism take
β-adrenergic-blocking drugs can be used to manage symptoms of thyrotoxicosis such as tremor and tachycardia
Give examples of antithyroid drugs
thioureylenes,
carbimazole
propylthiouracil
How are antithyroid drugs work
By prevention of incorporation of iodine into the thyroid hormones levothyroxine and tri-iodothyronine
What considerations should we taken dentally in a patient with hyperthyroidism
Contra indication to the use of adrenaline
Opportunistic infection such as oral candidiasis may occur
