Hyperthyroidism Flashcards
What is another name for this?
Thyrotoxicosis
Symptoms:
Systemic symptoms? - 3
GI - 2
Motor - 2
Psychological - 3
Why do they usually not have a loss of appetite?
Hot
Thirsty
Weight loss
Diarrhoea
Vomiting
Tremor
Proximal weakness
Anxiety
Irritable
Emotional lability refers to rapid, often exaggerated changes in mood, where strong emotions or feelings (uncontrollable laughing or crying, or heightened irritability or temper) occur..
As increased metabolism means they eat more
Symptoms:
What happens to women’s menstrual cycle?
Dermatological - 2
Become lighter and less frequent - can also cause 2* amenorrhoea
Hair loss
Itch
Signs:
Hands - 2
CV - 2
Eyes - why might they look like they are staring? - 2
How may their skin feel?
What is a thyroid bruit?
What autoimmune diseases should you ask about?
Palmar erythema due to increased cutaneous blood flow
Fine tremor
Tachycardia (PALPATATIONS) and AF
Lid retraction (exposure of sclera above the iris, causing stare) Lid lag
Warm and moist
A thyroid bruit is described as a continuous sound that is heard over the thyroid mass. (If you only hear something during systolic, think about a carotid bruit or radiating cardiac murmur.) A thyroid bruit is seen in Grave’s disease from a proliferation of the blood supply when the thyroid enlarges.
T1DM, Addison’s etc.
Signs of Graves:
What is found in the neck?
How does it feel?
(1) Graves ophthalmopathy:
- What may exacerbate the lid retraction?
- They also get weakening of the eye muscles. What is this called?
(2) Pretibial myxoedema:
- What is it?
(3) Thyroid acropachy (rare):
- What 3 things make up this?
Ophthalmoplegia
Diffuse, non-tender, firm goitre
Goitre should feel smooth - if it is hard and craggy, it could be multiple nodular or cancer
Exophthalmos
Purple/red oedematous swelling above the malleoli - so the front part of the lower leg
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Clubbing
Soft tissue swelling of the hands and feet
Periosteal new bone formation.
Causes:
Graves disease is the most common:
- What autoantibody is made?
- How does the autoantibody lead to hyperthyroidism?
- What type of goitre does it lead to?
- What is the typical age group?
- What are some triggers of this?
Thyrotropin-receptor antibody is an autoantibody to the thyroid cell receptor for TSH.
It activates the TSH receptor in the thyroid gland (IgG) and orbital pre-adipocytes (IgM).
A diffuse toxic goitre
Tend to be younger women
Stress
Infection
Childbirth
Causes:
Toxic multinodular goitre:
- What is the typical age group?
- What do the nodules do?
Toxic adenoma:
- What is it?
- What does it look like on an isotope scan?
What visual field defect can occur due to pituitary tumour?
Older patients
It is a solitary nodule producing T3 and T4
‘Hot’ meaning it is more active than the rest of the gland
Bitemporal heminiopia - due to compression of the optic chiasm
Other rarer causes:
Subacute de Quervain’s thyroiditis:
- What is it triggered by?
- Do they get a goitre?
Subacute lymphocytic thyroiditis:
- Painful/painless?
What obs event may cause thyroiditis?
Why does THYROIDITIS cause hyper T anyway?
Why does amiodarone cause hyperthyroidism?
Viral infection (mumps/flu)
Painless enlargement
Postpartum thyroiditis
Due to amiodarone’s high iodine content and its direct toxic effect on the thyroid.
What may compression by goitre lead to? - 3
Dysphagia
SOB +/- stridor
Hoarseness due to compression of recurrent laryngeal nerve
Investigations:
Bloods:
TSH is low and T4 is raised. What may cause TSH to be raised?
What 2 blood tests can be done for Graves disease?
Imaging:
- When is a USS done?
- FNA may be needed, for solitary nodules, which are more likely to be malignant than multiple nodules. What does FNA stand for?
Thyroid scan:
- Will Graves be high uptake or low uptake?
- Will thyroiditis be high uptake or low uptake?
Pituitary hyperthyroidism - tumour secreting TSH
TSH receptor antibodies
TPO antibodies
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If nodules are suspected
Fine needle aspiration for testing
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High uptake - high activity - called ‘HOT’
Low uptake - low activity - thyroid is leaking hormones instead of releasing them metabolically - called ‘COLD’
Management:
(1) Drugs:
What drug is given for rapid control over sympathetic-mediated symptoms such as tachycardia and diarrhoea?
(2) Antithyroid thioamide drugs:
- What are the name of the 2 drugs used? - C, P
- They work by suppressing function via 2 methods:
- Block and replace - what does this mean?
- Dose titration - what does this mean? why is this not preferred?
- Patients have a risk of agranulocytosis with commencement of C. How does this present?
Beta-blockers - propranolol
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Carbimazole
Propylthiouracil
‘Block and replace’ - completely suppress function with thioamide and given levothyroxine to replace T4
Dose titration - You only give thioamide
Not preferred as you need more monitoring and you may exacerbate eye disease with iatrogenic hypothyroidism.
Agranulocytosis may occur at any stage during treatment with Carbimazole and without warning. Patients are advised to immediately report symptoms of infection, such as a sore throat or fever, so that a full blood count test may be arranged. If this confirms a low neutrophil count, discontinuation of the drug leads to recovery. However, failure to report suggestive symptoms or delays in considering the possibility of immunosuppression and its testing can lead to fatalities.
Management:
(3) Radioactive iodine:
- How does it work?
(4) Thyroidectomy:
- List some indications?
- Why nerve could be damaged and what would the effect of this be?
Radioactive iodine is taken up by the thyroid and destroys the cells in the thyroid gland. This has the effect of reducing the amount of thyroxine made by the thyroid gland and may also reduce the size of the gland.
Malignancy
Compression goitre
Rx contraindicated
Recurrent laryngeal nerve - hoarse voice
Thioamides:
Name the 2 drugs used?
How long does it take to take effect?
Side effects - The main serious side effect is agranulocytosis:
- What is it?
- How does it present?
- What dangerous thing can it lead to?
Several weeks
Carbimazole
Propylthiouracil
Agranulocytosis is an acute condition involving a severe and dangerous leukopenia (lowered WBC count), most commonly of neutrophils, and thus causing a neutropenia in the circulating blood
Sore throat
Ulcers
Fever
Can lead to sepsis - the immune system is compromised
Thioamides:
Choice of the drug:
Which one is the first line?
Which one is the first line in pregnancy?
Carbimazole
Propylthiouracil
Complications:
Acute complication - 1
Chronic:
- Why do they get HF?
- Why do they get angina?
- What arrhythmia are they also likely to get?
- Why does osteoporosis occur?
- Why may an increased ratio of oestrogens to androgens cause?
Thyroid storm
By forcing the heart to work harder and faster, an overactive thyroid can overtax it and cause heart failure, a condition in which the heart can’t pump enough blood to meet the body’s needs.
If you already have high blood pressure which has in turn caused narrows arteries, the combination of a quicker, more forceful heartbeat caused by hyperthyroidism can cause angina.
Increased bone resorption. This happens too fast and the osteoblasts may not be able to replace the bone loss quickly enough.
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Gynecomastia by the increase in SHBG, causing the reduction of free testosterone.
