Thyroid disease: Hyper, Hypo and other Flashcards
Define Hypothyroidism
Underproduction of thyroid hormone
Primary Hypothyroidism is due to what type of problem?
thyroid problem
Secondary Hypothyroidism is due to what type of problem?
hypothalamic/pituitary problem
Define Hyperthyroidism
overproduction of thyroid hormone
What is thyrotoxicosis ?
Thyrotoxicosis refers to the symptoms caused by the excessive circulation of thyroid hormones.
Define Euthyroid
normal production of thyroid hormone
Define Goitre
enlargement of thyroid gland
patients with a goitre may be: (3 things)
hyperthyroid, hypothyroid, euthyroid (normal thyroid function)
Examination of the thyroid
low down in neck feel for thyroid cartilage (‘Adam’s apple) then down and laterally moves on swallowing diffuse or nodular? listen for a bruit retrosternal extension (can you get below it? percuss over sternum) check cervical LNS
What does this image show?
X-ray of Retrosternal goitre causing tracheal deviation
Interpreting thyroid function tests
remember …
the thyroid axis and negative feedback regulation
what is not working properly?
what is driving the system?
Thyroid function tests are extremely common, … in every … have there thyroid function checked annually
1 in every 4
Normal thyroid function test ranges (info)
TSH?
FT4?
FT3?
What Thyroid antibodies are tested?
0.3 - 4.2 mu/l
12-22 pmol/l
3.1-6.8 pmol/l
Anti-TPO AB - thyroid peroxidase auto-antibody
TRAB - TSH receptor autoantibody
What are the two thyroid antibodies?
Anti-TPO AB - thyroid peroxidase auto-antibody
TRAB - TSH receptor autoantibody
Thyroid stimulating hormone is the best …
biomarker of thyroid status
Shape of TSH curve
- there is a tail from … upwards
- in this population, more patients have what?
tail from 3 upwards
increased frequency of thyroid antibodies
TSH is quite … to respond to change - takes about … weeks
slow - takes about 6 weeks
TSH assumes a normal … function
pituitary
must measure free thyroid hormones in patients with pituitary problem
Thyroid autoantibodies
The prevalence of autoantibodies is … than the prevalence of autoimmune disease
- some are causal in disease, whereas some are viewed as a marker of …
- many auto antigens are sequestered / …
- negative autoAB result does not exclude …
higher
risk marker
intracellular
the disease - presence just helps confirm diagnosis
Different types of thyroid autoantibodies
- “…” - target thyroid for autoimmune …
- “…” - stimulate TSH receptor (TRAB)
- destructive
- stimulatory
What are the symptoms below a sign of?
- may be none
- lethargy
- mild weight gain
- cold intolerance
- constipation
- facial puffiness
- dry skin
- hair loss
- hoarseness
- heavy menstrual periods
hypothyroidism
Severe hypothyroidism signs include:
- Change in appearance e.g face is puffy and pale
- periorbital oedema
- dry flaking skin
- diffuse hair loss
- bradycardia
- signs of median nerve compression - carpal tunnel
- effusions, e.g. ascites, pericardial
- delayed relaxation of reflexes
- croaky voice
- goitre
- rarely stupor or coma
The symptoms below are a sign of what?
- Change in appearance e.g face is puffy and pale
- periorbital oedema
- dry flaking skin
- diffuse hair loss
- bradycardia
- signs of median nerve compression - carpal tunnel
- effusions, e.g. ascites, pericardial
- delayed relaxation of reflexes
- croaky voice
- goitre
- rarely stupor or coma
severe hypothyroidism
Causes of Primary Hypothyroidism include: (6 things)
High TSH, low T4, low T3
- autoimmune hypothyroidism
- hypothyroidism after treatment for hyperthyroidism (iatrogenic)
- thyroiditis
- drugs (e.g. lithium, amiodarone)
- congenital hypothyroidism
- iodine deficiency (NOT UK)
Causes of Secondary Hypothyrodism is …
- Caused by diseases of the … or …
- Low TSH, low T4, low T3
- rare
- Diseases of they hypothalamus or pituitary
Investigations - Primary hypothyroidism
- Bloods - TSH (normal range 0.3-4) and FT4 (normal range 10-24) ,what results would be expected?
- Do these confirm the diagnosis?
- What else could we check?
- Is imaging necessary?
Higher TSH (E.g. 22miu/l) and Lower FT4 (e.g. 8pmol/l)
- yes - diagnosis confirmed with blood results
- could also check thyroid autoantibodies
- no imaging is necessary
Treatment for hypothyroidism
- start with …, … micrograms daily (Depending on size/weight of patient)
- if patient has ischaemic heart disease or is over 65 - start with less (…-… micrograms daily) with increments 4-6 weekly
- USUAL DOSE = ?
- the aim is to achieve a normal … level without … suppression
- no evidence in properly conducted trials to support combination therapy of … and …
- start with thyroxine, 100micrograms
- use less in these patients - 25-50 micrograms to begin with
- usual dose is 100-150 micrograms
- aim - normal FT4 without TSH suppression
- no evidence for combo of T3 and T4
Chronic autoimmune thyroiditis
- also known as … disease
- this term is used to imply that the patient has a … or that their thyroid shows signs of … infiltration
- hashimoto’s disease
- this term is used to imply that the patient has a goitre or that their thyroid shows signs of thyroid infiltration
Myxoedema (coma)
- the accumulation of … in interstitial spaces of tissues
- it is a very … type of …thyroidism
- glycosaminoglycans
- very severe hypothyroidism
What are the symptoms below a sign of?
- weight loss
- lack of energy
- heat intolerance
- anxiety/irritability
- increased sweating
- increased appetite
- thirst
- palpitations
- pruritus
- weight gain
- loose bowels
- oligomenorrhoea
thyrotoxicosis / hyperthyroidism
Symptoms of thyrotoxicosis (hyperthryoidism) include:
- weight loss
- lack of energy
- heat intolerance
- anxiety/irritability
- increased sweating
- increased appetite
- thirst
- palpitations
- pruritus
- weight gain
- loose bowels
- oligomenorrhoea
Signs associated with thyrotoxicosis: (8)
- tremor
- warm, moist skin
- tachycardia
- brisk reflexes
- eye signs
- thyroid bruit
- muscle weakness
- atrial fibrilation
What are the signs below associated with?
- tremor
- warm, moist skin
- tachycardia
- brisk reflexes
- eye signs
- thyroid bruit
- muscle weakness
- atrial fibrilation
thryotoxicosis/hyperthyroidism
Thyroid eye disease (TED) / thyroid associated ophthalmopathy (TAO)
- Associated with autoimmune … (known as … disease) in approx 20% of patients
- They may not occur at same time, or at all
- increased risk in …
- … mediated
- inflammation of all orbital tissues except the …
- … scan imaging helpful
- Associated with autoimmune hyperthyroidism (known as grave’s disease) in approx 20% of patients
- They may not occur at same time, or at all
- increased risk in smokers
- autoantibody mediated
- inflammation of all orbital tissues except the eye
- CT scan imaging helpul
Symptoms of thyroid eye disease (TED) / thyroid associated ophthalmopathy (TAO)
Mild:
- eyes are … / …
- artificial … may help
- ‘….’ eyes / change in appearance
- eyes are dry/ itchy
- artificial tears may help
- ‘prominent’ eyes / change in appearance
Symptoms of thyroid eye disease (TED) / thyroid associated ophthalmopathy (TAO)
Worrisome:
- loss of sight / …
- loss of … vision (patches are …/…)
- swelling of …/redness
- unable to … eyes fully
- ache/pain/tightness … or … eye
- loss of sight /diplopia
- loss of colour vision (patches are grey/blurred)
- swelling of conjunctiva/redness
- unable to close eyes fully
- ache/pain/tightness in or behind eye
What is shown in this image? (eyes - thyroid eye disease)
- MRI T2 weighting STIR sequencing
- shows inflammatory activity of extraocular muscles
What disease is present?
thyroid eye disease
Signs associated with thyrotoxicosis:
- Hands (2 signs)
- fine tremor
- warm
Signs associated with thyrotoxicosis:
- Pulse (2 signs)
- sinus tachycardia
- atrial fibrillation
Signs associated with thyrotoxicosis:
Neck (4 signs)
- goitre
- move when swallow
- smooth/not
- bruit/not
Signs associated with thyrotoxicosis:
Eyes (4 signs)
- lid retraction/lag
- proptosis/exophthalmos
- ophthalmoplegia (abnormal eye movements, causes diplopia)
- inflammation (conjunctiva)
What is diplopia?
technical term for double vision.
What is Ophthalmoparesis?
refers to weakness (-paresis) or paralysis (-plegia) of one or more extraocular muscles which are responsible for eye movements.
What is proptosis/exophthalmos?
Exophthalmos, also known as proptosis, is the medical term for bulging or protruding eyeballs.
Causes of thyrotoxicosis
- most common cause is … … (also known as what disease?)
- what happens in this disease? (autoantibody….)
- named after doctor who discovered it
- accounts for …% of hyperthyroidism, typically women of what age?
- Autoimmune hyperthyroidism (Grave’s disease)
- autoantibody stimulates the TSH receptor, causing excess thyroid hormone production and thyroid growth (goitre)
- 75% of hyperthyroidism - typically women 30-50 yrs
Other causes of thyrotoxicosis (4 things)
- toxic … goitre
- toxic …
- thyroiditis
- drugs (such as…)
- toxic multinodular goitre
- toxic adenoma
- thyroiditis
- drugs (E.g. amiodarone)
Main cause is autoimmune hyperthyroidism
Gestational thyrotoxicosis
- HCG made by the … has a very similar structure to …
- more likely if hyperemesis (morning sickness) / twin pregnancy
- settles after … trimester
- HCG made by the placenta has a very similar structure to TSH
- more likely if hyperemesis / twin pregnancy
- settles after 1st trimester
Helpful diagnostic features (Cause of hyperthyrodism)
more likely to be Grave’s disease if:
- … or … hx of any autoimmune thyroid/endocrine disease
- Goitre with a …
- 20% of those with … have grave’s disease
- positive thyroid … titre
- Personal or family history
- Goitre with a bruit
- thyroid eye disease
- positive thyroid autoantibody titre
Thyroid function tests for hyperthyroidism (e.g. Grave’s disease)
- TSH < 0.1 miu/l (hyperthyroidism) vs normal range? higher or lower in hyperthyroidism?
- FT4 30pmol/l (hyperthyroidism) vs normal range? higher or lower in hyperthyroidism?
- FT3 10pmol/l (hyperthyroidism) vs normal range? higher or lower in hyperthyroidism?
- TSH < 0.1 miu/l (hyperthyroidism) what is normal range? - 0.3-4 (lower in hyperthyroidism)
- FT4 30pmol/l (hyperthyroidism) what is normal range? - 10-24 (higher in hyperthyroidism)
- FT3 10pmol/l (hyperthyroidism) what is normal range? - 3-7 (higher in hyperthyroidism)
remember the negative feedback loop
TSH suppressed because thyroid overactivity is supressing TSH production
Further investigations for hyperthyroidism (after thyroid function tests)
- thyroid …
- may not need any …
- thyroid … scan (isotope scan)
- functional scan - darker areas of … activity
- thyroid autoantibodies
- may not need any imaging
- thyroid uptake scan (isotope scan)
- functional scan - darker areas of increased activity
Grave’s disease treatment options include: (4 things)
- …
- …
- …
- … control - use … blockers but not in people who are …
OR - no treatment - what are the risks?
- medical
- radioiodine
- surgery
- symptom control (beta blockers - propranolol but not if asthmatic)
OR - no treatment - what are the risks?
- symptoms worsening
- AF -> stroke
- osteoporosis -> fractures
Medical Therapy for Grave’s disease
- 2 drug examples, what are they?
- how long do you treat for?
- you can block replace or …
- rare side effect is …
- What is the long term cure rate?
- how many relapse?
- carbimazole or propylthiouracil (PTU)
- 18 months - 2 years
- titrate or block replace
- agranulocytosis is a rare side effect
- 1/3 long term cure rate
-
2/3 relapse - usually in first year, cannot predict in advance
*
What is Agranulocytosis?
A rare condition in which your bone marrow doesn’t make enough of a certain type of white cell, most often neutrophils.
Radioiodine therapy for Grave’s disease
- it is given …
- radioiodine is concentrated in the … and kills … cells
- medical therapy first until thyroid status is …
- approx 40% risk of permanent … after treatment
- do not give if … or breast feeding
- need to avoid prolonged close contact with others for … - … weeks after - tricky if young children
- not if severe … … disease
- future pregancies - women wait … months, men … months
- warn patients about … security systems
- it is given orally
- radioiodine is concentrated in the thyroid and kills thyroid cells
- medical therapy first until thyroid status is euthyroid
- approx 40% risk of permanent hypothyroidism after treatment
- do not give if pregnant or breast feeding
- need to avoid prolonged close contact with others for 1 - 2 weeks after - tricky if young children
- not if severe thyroid eye disease
- future pregancies - women wait 6 months, men 4 months
- warn patients about airport security systems
Surgery for Grave’s disease
- sub-total … (“almost total”)
- patients must be … pre-op
- medical therapy first
- risks include:
- …
- … scar
- vocal cord … (recurrent laryngeal nerve damage)
- hypothyroidism
- hypoparathyroidism
- sub-total thyroidectomy (“almost total”)
- patients must be euthyroid pre-op
- medical therapy first
- risks include:
- anaesthetic
- neck scar
- vocal cord palsy
- hypothyroidism
- hypoparathyroidism
Treatment for a toxic adenoma or toxic multinodular goitre
- initial treatment - short term … therapy - to control thyroid function tests
- subsequent curative treatment - …
- initial treatment - short term medical therapy - to control thyroid function tests
- subsequent curative treatment - radioiodine
Agreeing expectations - treating hyperthyroidism
- reassurance that variety of symptoms all relate to condition e.g …
- may take time to feel normal again - there will be a ‘…’ phase of a few months
- treatments for thyroid do not help with … disease
- risk of weight …
- confirm family plans - why?
- swings in emotion, anxiety, panic, irritability
- lag phase
- eye disease - treatment doesnt help
- risk of weight gain
- starting a family - have to wait after radioiodine
Blood results - what condition did the person have before starting treatment?
What stays suppressed for a while? what is best to monitor?
Hyperthyroidism
TSH stays suppressed for some time - monitor FT4
Thyroid Eye Disease - treatment options
Active disease options include
- encourage … cessation
- steroids , examples?
- other immunosuppressive/ …-sparing agents
- …therapy
- encourage smoking cessation
- steroids - pulsed IV methylpred/ oral prednisolone
- other immunosuppressive/ steroid-sparing agents
- radiotherapy
Thyroid Eye Disease - treatment options
‘Burnt out’ thyroid eye disease:
- may be left with … causing impaired QOL and social avoidance
- treatment is … - 2 options are
- may be left with disfigurement causing impaired QOL and social avoidance
- treatment is surgical - 2 options are
- orbital decompression
- eyelid surgery
A rare but dangerous complication of Grave’s disease is called thyroid … or thyrotoxic …
thyroid storm or thyrotoxic crisis
Who gets thyrotoxic crisis (thyroid storm?)
is it common?
- usually secondary to grave’s
- unrecognised
- incompletely treated e.g. start stop, erratic compliance, early on in course, surgery/radioiodine treatment without adequate prep
- very rare
What triggers thyrotoxic crisis (thyroid storm?) (3 things)
- surgery (GA)
- childbirth
- acute severe illness such as infection, trauma, diabetic ketoacidosis, stroke, PE
Features of thyroid storm
- It is a …-… condition
- typical features of … disease
- hyperpyrexia
- CNS - agitation, delirium
- CNS symptoms include (4 things)
- GI symptoms include (3 things)
- It is a multi-system condition
- typical features of grave’s disease
- hyperpyrexia
- CNS - agitation, delirium
- CNS symptoms include (4 things)
- tachycardia >140bpm
- atrial dysrhythmias
- ventricular dysfunction
- heart failure
- GI symptoms include (3 things)
- nausea and vomiting
- diarrhoea
- hepatocellular dysfunction
What is hyperpyrexia?
A term for a very high fever
(occurs in thyroid storm)
Thyroid storm has a … mortality rate and involves … level care
High mortality rate and involves ITU-level care
Does degree of elevation of thyroid hormone concentrations distinguish between uncomplicated thyrotoxicosos and thyroid storm?
NO - does not distinguish - harder to recognise
Thyroiditis
- To begin, transient mild …
- always …
- B-blockers if required
- isotope scan would be ‘…’
- anti-thyroid drugs - do they work?
- longer phase of what? (4-6months)
- what % are normal within a year?
- what treatment may be required for a while? (during this phase)
- transient mild thyrotoxicosis
- always resolves (1-2months)
- B-blockers if required
- isotope scan would be ‘cold’
- anti-thyroid drugs - do they work? - no
- longer hypothyroid phase (4-6months)
- 80% normal at 1 year
- may require thyroxine treatment for a while
Annual TFTs for thyroiditis patients:
- What % hypothyroid at 1 year?
- What % hypothyroid at 3 years?
- What % hypothyroid at 1 year? - 30%
- What % hypothyroid at 3 years - 50%
Thyroiditis, consider if:
- patient is …/ within one year …-…
- increased risk in type 1 …, FHx of thyroid …, smoker
- patient has a very … thyroid
- may be raised … markers
- clinical thyroid status does not fit with lab results, why?
- no diagnositic features of … disease
- current/recurrent treatment with … medication
- patient is pregnant/ within one year post-partum
- increased risk in type 1 diabetes, FHx of thyroid disease, smoker
- patient has a very tender thyroid
- may be raised inflammatory markers
- clinical thyroid status does not fit with lab results, why? - rapidly changing thyroid function tests
- no diagnositic features of grave’s disease
- current/recurrent treatment with immunomodulatory medication
Thyroid function tests - what condition? (thyroid)
- baby in Jan
postpartum thyroiditis
initially, low TSH, high FT4 - thyrotoxic - mildy
then, hypothyroid phase - high TSH, low FT4
Association of autoimmune thyroid disease with other diseases
other autoimmune endocrine diseases include: (5)
- … . …
- … …
- … disease
- … … …
- … disease
syndromes: (2)
- … syndrome
- …’s syndrome
Medication for other diseases:
- lithium - what does this do?
- amiodarone
Annual Thyroid function test screening recommended in all of these situations
- Type 1 diabetes
- Pernicious anaemia
- Coeliac disease
- Premature ovarian failure
- Addison’s disease
- Turner syndrome
- Down’s syndrome
- lithium - inhibits Thyroid hormone synthesis and secretion
- amiodarone
Goitre and thyroid nodules in euthyroid patients
Euthyroid Goitre:
- is it common?
- where is it common?
- may be …
- usually nothing to worry about
Thyroid nodule:
- must exclude thyroid … - 5% cancerous, rest benign
- … scan characterists helpful
- fine-needle … biopsy for cytology
Euthyroid Goitre:
- is it common? - yes
- where is it common - in iodine-deficient areas
- may be multinodular
- usually nothing to worry about
Thyroid nodule:
- must exclude thyroid cancer - 5%
- ultrasound scan characterists helpful
- fine-needle aspiration biopsy for cytology
