case 13 - tiredness Flashcards

1
Q

what main conditions can cause tiredness?

A
  • blood-related = anaemia, underactive thyroid, coeliac disease, diabetes, glandular fever
  • head-related = depression, anxiety
  • sleep-related = chronic fatigue syndrome, sleep apnoea, restless legs syndrome
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what’s the difference between tiredness and fatigue?

A
  • tiredness = can be relieved by sleep and rest
  • fatigue = overwhelming tiredness that cannot be relieved by sleep and rest
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what type of anaemias are associated with tiredness?

A
  • iron-deficiency anaemia (most common)
  • vitamin B12 or folate deficiency anaemia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

who is at a high risk of developing iron-deficiency anaemia?

A
  • women with heavy periods (menorrhagia)
  • pregnant women
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is the most common cause of anaemia in men and postmenopausal women?

A

problems with the stomach and intestines

e.g. ulcer OR taking NSAIDs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

why and how can NSAIDs cause anaemia?

A
  • decrease the activity of blood platelets = decreased clot formation
  • increased risk of bleeding and ulcer formation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is an ulcer?

A

a localised sore in the skin or mucous membrane (stomach, small intestine, oesophagus)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

besides anaemia, which (opposite) blood condition can cause tiredness?

A

haemochromatosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is haemochromatosis?

A
  • rare inherited condition
  • build-up of iron in the body leading to iron-overload
  • deposition in the liver, joints, pancreas etc
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

who does haemochromatosis affect most?

A

men and women between 30-60

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is sleep apnoea?

A

a condition where your throat narrows or closes during sleep and repeatedly interrupts your breathing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what does sleep apnoea result in?

A

loud snoring

decrease in blood oxygen levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the main symptoms/impact of sleep apnoea?

A

waking up often during the night

feeling exhausted the next day (due to disrupted sleep)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

who is affected by sleep apnoea the most?

A

overweight middle-aged men

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what factors worsen sleep apnoea?

A

increased alcohol and smoking

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is an underactive thyroid?

A

thyroid hormone (T3 and T4) deficiency

due to reduced production by the thyroid gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

besides tiredness, what are the additional symptoms of an underactive thyroid?

A
  • weight gain
  • aching muscles
  • dry skin
  • low mood
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is an underactive thyroid alternatively known as?

A

hypothyroidism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

how can an underactive thyroid be diagnosed?

A

blood test (to test TSH, T4 levels)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

who is most likely to be affect by hypothyroidism?

A

women as they get older

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is coeliac disease?

A

autoimmune condition wherein the immune system overreacts to the gluten ingested in the diet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is gluten?

A

a protein in wheat, barley and rye

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

which foods are gluten-rich?

A

can be found in foods like pasta, bread, cakes and cereals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

besides tiredness, what are the symptoms of coeliac disease?

A
  • diarrhoea
  • anaemia
  • bloating
  • weight loss
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

how is coeliac disease diagnosed?

A

blood test

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what is chronic fatigue syndrome?

A

severe and disabling fatigue for at least 4 months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what is chronic fatigue alternatively known as?

A

myalgic encephalomyelitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

besides tiredness, what are the other symptoms of ME?

A

muscle or joint pain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

which diabetes is tiredness a symptom of?

A

type 1 and type 2 diabetes both

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

besides tiredness, what are the symptoms of diabetes (type 1)?

A
  • polydipsia
  • polyuria
  • nocturia
  • weight loss
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what is glandular fever/mononucleosis?

A

a common viral infection that causes fatigue, fever, sore throat and swollen glands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

who is most affected by glandular fever?

A

teenagers and young adults

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

how long does glandular fever last?

A

symptoms usually clear up in 4-6 weeks but fatigue can linger for several more months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

how and why can depression cause tiredness?

A

core symptoms = anergia, anhedonia, low mood

can also cause disruption to sleep + early waking up = more tiredness during the day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

what is restless legs syndrome?

A

an overwhelming urge to move your legs, which can keep you awake at night

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

what are the symptoms of restless legs syndrome?

A

an overwhelming urge to move legs at night

unpleasant crawling sensation

deep ache in legs

legs may jerk spontaneously through the night

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

what is GAD?

A
  • generalised anxiety disorder
  • long-term condition that causes you to feel uncontrollably anxious about a wide range of situations and issues, rather than one specific event
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

who is most commonly affected by GAD?

A

common, affects women slightly more than men

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

to the nearest 10%, what percentage of patients who present to a GP with fatigue have a diagnosis made?

A

approx 66%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

to the nearest 10%, what percentage of patients who present to a GP have a condition that is detected on blood tests?

A
  • approx <10%
  • history and physical examination are important
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

how many GP consultations are due to fatigue?

A

approx 7%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

name five other possible differential diagnoses

A

jet lag disorder

pregnancy

(chronic) heart failure

insomnia

vitamin D deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

what is important to consider when thinking of possible differential diagnoses?

A
  • frequency e.g. common to rare
  • consequence e.g. less serious (e.g. nutritional deficiencies) to very serious (e.g. cancers)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

how do you narrow down to fewer/a maximum of two differential diagnoses?

A

asking more questions to get a more comprehensive history

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

which of the following blood tests would be ordered to investigate hypothyroidism?

FBC
U&E
vitamin D
TFTs
HbA1c
CRP
coeliac screen
autoimmune screen
EBV serology

A

FBC (full blood count)

U&E (urea & electrolytes)

vitamin D

TFTs (thyroid function tests)

HbA1c

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

why would a FBC be done to investigate tiredness?

A

to test for classic signs of anaemia, haematological malignancy and WBC levels for signs of infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

why would a U&E be done to investigate tiredness?

A

look at electrolyte abnormalities and eGFR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

why would a vitamin D test be done to investigate tiredness?

A

to test for vitamin D deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

why would TFTs be done to investigate tiredness?

A

to test for possible hypothyroidism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

why would HbA1c be done to investigate tiredness?

A

to test for abnormal glucose levels which could indicate diabetes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

why wouldn’t an autoimmune screen be done to investigate tiredness?

A

can be an extensive test that requires loads of time and effort so more justification is needed before requesting one

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

what do the following blood test results indicate and why?

A

indicate primary hypothyroidism due to the reduced fT3 and fT4 levels and the elevated TSH levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

what are the symptoms of hypothyroidism?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

explain the mechanism of action of primary hypothyroidism, using the HPA axis

A

decreased production of thyroid hormones by the thyroid gland causes a compensatory increase of TSH due to the negative feedback loop

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

what is primary hypothyroidism?

A
  • low levels of blood thyroid hormone due to destruction of the thyroid gland
  • destruction can be due to autoimmunity, surgery, radiation, medication etc
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

what is secondary hypothyroidism?

A

pituitary produces insufficient TSH (more common)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

what would be the expected TFT results for a patient with primary hypothyroidism?

A

low fT3 and fT4
elevated TSH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

what would be the expected TFT results for a patient with secondary hypothyroidism?

A

low fT3 and fT4
low TSH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

differentiate between primary and secondary hypothyroidism

A

primary = due to direct damage to the pituitary gland

secondary = due to pituitary or hypothalamic damage/disease

60
Q

what is tertiary hypothyroidism?

A

when the hypothalamus produces insufficient thyrotropin-releasing hormone (TRH)

reducing TSH and therefore fT3 and fT4 production downstream

61
Q

what is the most common type of autoimmune hypothyroidism?

A

Hashimoto’s thyroiditis

62
Q

how can you differentiate between secondary and tertiary hypothyroidism?

A

practically impossible to do so as TRH levels are immeasurable (as it is in the portal circulation, not the systemic circulation)

63
Q

name the immune cells

A

eosinophils
basophils
neutrophils
macrophages
dendritic cells
natural killer (NK) cells
B lymphocytes
T lymphocytes

64
Q

name the antigen-presenting cells

A

macrophages
dendritic cells
B cells

65
Q

explain the mechanism by which immune cells attack the thyroid cells in Hashimoto’s disease

A
66
Q

what are the ‘foreign’ antigens recognised by APCs in Hashimoto’s?

A

either TPO (thyroid peroxidase) or thyroglobulin

67
Q

how do APCs interact with T helper cells when a foreign antigen is recognised?

A

the TPO/Tg is presented in the MHC II molecules of APC to the TCRs of T helper cells

68
Q

what are MHC I molecules?

A

receptors on the surfaces of almost all somatic cells that present endogenous antigens to cytotoxic T cells

69
Q

what are MHC II molecules?

A

receptors on the surfaces of all antigen-presenting cells (dendritic cells, B cells, macrophages) that present exogenous antigens to T helper cells

70
Q

what is a TCR and what does it interact with?

A

protein complex found on the surface of T cells and is responsible for recognising and binding to foreign antigens

interacts with antigens presented on the MHC II molecules of APCs

71
Q

what is T cell co-stimulation?

A

a secondary signal which T cells rely on to activate an immune response in the presence of an antigen-presenting cell

= specifically when B7 on APCs binds to CD28 on T helper cells

72
Q

how does a T cell process the foreign antigen in Hashimoto’s?

A

presents the TPO/Tg foreign antigen to the MHC IIs of B cells via the TCRs

73
Q

how do T helper cells interact with B cells when a foreign antigen is recognised?

A
  • the TPO/Tg foreign antigen is presented on the TCRs molecules of T cells to the MHC IIs of the B cells
  • simultaneously, B-cell co-stimulation takes place when CD40L on T cells binds to CD40 on B cells
74
Q

what is B cell co-stimulation?

A
  • a secondary signal which B cells rely on to activate an immune response
  • when CD40L on T cells binds to CD40 on B cells
75
Q

which receptors interact in T cell co-stimulation?

A

B7 on APCs with CD28 on T helper cells

76
Q

which receptors interact in B cell co-stimulation?

A

CD40L on T helper cells with CD40 on B cells

77
Q

how do B cells respond after activation and B cell co-stimulation in Hashimoto’s?

A

produce anti-TPO/anti-thyroglobulin (anti-Tg) antibodies to attack the thyrocytes

78
Q

what are anti-TPO antibodies?

A

antibodies that are produced against and attack the thyroid peroxidase (TPO) enzyme, which normally facilitates the production of thyroxine

79
Q

what are anti-thyroglobulin antibodies?

A

antibodies produced against thyroglobulin (store for the inactive forms of the thyroid hormone in the follicular cells)

80
Q

how are thyrocytes attacked in Hashimoto’s?

A

upon activation, T helper cells can further activate cytotoxic T cells that go on to attack the thyrocytes

81
Q

differentiate between exogenous and endogenous antigens

A

exogenous = antigens that enter from outside the body, such as bacteria, fungi, protozoa, and free viruses (MHC II)

endogenous = antigens found within the cytosol of human cells such as viral proteins, proteins from intracellular bacteria, and tumor antigens (MHC I)

82
Q

what is immune tolerance and where does it occur?

A

central tolerance (both B cells and T cells) = the process of eliminating any self-reactive B/T lymphocytes

  • B cell central tolerance occurs in the bone marrow: negative selection only
  • T cell central tolerance occurs in the thymus: positive and negative selection both
83
Q

how does immune tolerance take place in terms of adaptive immunity?

A

during development, B cells in the bone marrow and T cells in the thymus are exposed to the entire protein repertoire of the body = to prevent them from recognising self antigens as foreign AND any self-reactive lymphocytes are destroyed early on

(central tolerance in the primary lymphoid organs)

84
Q

how does immune tolerance take place in terms of innate immunity?

A
  • granulocytes (neutrophils, basophils, eosinophils), macrophages and dendritic cells only attack cells that display PAMPs (pathogen-associated molecular patterns)
  • NK cells attack only cells that do not display MHC I molecules (which all somatic cells display normally)
85
Q

why do normal granulocytes, dendritic cells and macrophages not attack body cells?

A

only attack cells that display PAMPs (pathogen-associated molecular patterns)

86
Q

why do normal natural killer cells not attack body cells?

A

natural killers cells attack only cells that do not display MHC I molecules (which all somatic cells display normally)

87
Q

when do autoimmune diseases occur?

A

when the immune system attacks the body’s own cells, considering them to be foreign

(can be due to molecular mimicry, environmental triggers, genetic predisposition, high stress levels)

88
Q

what is molecular mimicry?

A

when a foreign cells display antigens that resemble host antigens and so host antigens are mistaken as being foreign and responded to inappropriately

89
Q

what are T regulatory cells and why are they important?

A

a subpopulation of suppressive T cells, T regulatory cells (Treg cells) are potent mediators of self-tolerance + essential for the suppression of triggered immune responses if the antigen is a host antigen

90
Q

what are the steps to addressing tiredness in a GP setting?

A
  • step 1 = define type of tiredness
  • step 2 = why did this patient present?
  • step 3 = screen for red flags
  • step 4 = explore any psychosocial triggers
  • step 5 = examine the patient
  • step 6 = initial bloods
  • step 7 = management of persisting unexplained tiredness with normal initial bloods
91
Q

what are the types of tiredness?

A

drowsiness, short of breath, weakness

92
Q

which one is more worrying?

1) ‘i feel okay when i wake up, but it gets worse as i do things’
2) ‘i feel rubbish when i wake up, but it gets better as i do things’

A

first one is more worrying = exertional tiredness is far more likely to be physical

93
Q

what is important to assess initially when a patient presents with tiredness?

A

look for functional impairment (e.g. unable to make dinner for family)

94
Q

what are the red flag symptoms associated with tiredness?

A
  • lymphadenopathy
  • unintentional weight loss
  • specific malignancy features (lung, breast, colon, upper GI and gynae)
  • joint pains and muscle aches
  • focal neurology
  • infective symptoms (glandular fever, TB, lyme disease)
95
Q

what are possible psychosocial triggers for tiredness?

A

workload, money, family, mood, drugs & alcohol

96
Q

how is a patient usually examined for tiredness?

A

dependent on history but at minimum: pulse, blood pressure and BMI

97
Q

which bloods are taken initially from a patient presenting with tiredness?

A

FBC, TFTs, ESR, glucose

notes
- FBC = not just for anaemia, but also for iron deficiency and haematological malignancy

  • in non-anaemia, menstruating women, treating a low ferritin can improve tiredness
  • lymphomas often have normal WBC count in early stages
98
Q

answer the following question posed by a patient with hypothyroidism:

‘what are the side effects of treatment? how can i cope with them?’

A

levothyroxine doesn’t usually have any side effects as the tablets are simply replacing a missing hormone

side effects would usually occur if you’re taking too much levothyroxine which can cause problems including sweating, chest pain, headaches, diarrhoea and vomiting

(if symptoms develop then you should consult your doctor)

99
Q

answer the following question posed by a patient with hypothyroidism:

‘what are the chances that someone else in my family will get an underactive thyroid? does it run in families?’

A

underactive thyroid is often caused by an autoimmune disease that can run through families

100
Q

what are some common causes of an underactive thyroid gland?

A
  • autoimmune damage, Hashimoto’s thyroiditis
  • temporarily after giving birth
  • radioactive iodine treatment or surgery to correct hyperthyroidism
  • antithyroid drugs
  • medicines like lithium and amiodarone
  • some cough medicines containing large amounts of iodine
  • some health foods taken in excess e.g. kelp
  • malfunction of the pituitary gland
  • radiation for head and neck cancers, not so common in UK
  • congenital hypothyroidism = present from birth
101
Q

what is the spectrum of symptoms experienced due to an underactive thyroid gland?

A

some people don’t notice symptoms or have very mild symptoms that gradually develop

while others feel tired and low, have dry skin and hair loss

102
Q

what is hormone replacement therapy for an underactive thyroid called?

A

levothyroxine (tablet)

103
Q

how is levothyroxine taken?

A

tablet once a day on an empty stomach, usually before breakfast

104
Q

how is the optimal dose of levothyroxine determined?

A

needs to be adjusted carefully to prevent administering too much

begin with a low dose that is gradually increased as required with regular monitoring through blood tests

105
Q

how long does levothyroxine take to improve symptoms?

A

may take several weeks/months before you notice any difference in your symptoms

will have regular thyroid function tests during this time to inform dose adjustment

106
Q

what can too much levothyroxine cause?

A

atrial fibrillation (abnormal heartbeat) or thinning of bones

107
Q

how are patients with mildly underactive thyroid glands managed?

A

might not need to take thyroxine straight away

= may have your thyroid level checked regularly

108
Q

what is congenital hypothyroidism?

A

hypothyroidism being present from birth

in some babies, the thyroid gland is underdeveloped and so there is a lack of thyroid hormone

109
Q

how can hyperthyroidism lead to hypothyroidism?

A

treatment for hyperthyroidism (radioactive iodine therapy, surgery, antithyroid drugs) can lead to hypothyroidism if administered in excess

110
Q

how is hypothyroidism diagnosed?

A

physical examination and blood tests

  • physical examination = look for enlarge thyroid gland, brittle nails, hair loss, dry skin etc
  • TFTs = assess TSH levels and fT3 and fT4 levels; can also test for thyroid antibodies (to confirm if the cause is autoimmune)
111
Q

what is mild thyroid failure?

A

when the level of hypothyroidism so small that there are no obvious symptoms and can only be detected by blood test

112
Q

what is mild thyroid failure also known as?

A

subclinical hypothyroidism

113
Q

how is mild thyroid failure/subclinical hypothyroidism detected and diagnosed?

A

can be discovered as a result of blood tests for another autoimmune disorder or because there is a history of thyroid disorders in the family

blood test = raised TSH with a normal fT4

114
Q

how should subclinical hypothyroidism be managed?

A

regular thyroid function test and consult doctor if noticing any symptoms

115
Q

what is levothyroxine?

A

a synthetic version of the thyroxine produced by the thyroid gland

116
Q

what are the side effects of levothyroxine?

A

very pure, has negligible side effects when taken in the correct dose

117
Q

how is levothyroxine dose determined normally?

A

doses are dependent upon the person’s body weight and their blood test results

most patients require between 100 and 150mcg a day, but the dose can be lower than 75mcg or up to
300mcg a day, depending on your needs

118
Q

how is levothyroxine dose determined in severe hypothyroidism?

A

if severe hypothyroidism or risk of heart problems, doctor will start cautiously + increase dose gradually.

119
Q

which drugs can decrease levothyroxine absorption and how is this prevented?

A

calcium, iron, orlistat and multivitamin tablets

prevented by taking on an empty stomach

120
Q

which substances can decrease levothyroxine absorption and how?

A

grapefruit, as it increases acidity in the stomach

121
Q

what happens if you miss a dose of levothyroxine?

A

your body has a big reservoir of thyroxine so you will not notice a difference

122
Q

what are the desired blood results for patients with hypothyroidism?

A
  • a TSH reading in the lower part of the reference range
  • fT4 reading towards the upper part or even slightly above the reference range
123
Q

what is combined LT3 and LT4 therapy?

A

combo therapy of levothyroxine and tri-iodothyronine (LT4 and LT3) may be considered as an experimental approach under the supervision of an accredited endocrinologist

= if symptoms persist despite levothyroxine administration

124
Q

why is LT3 not commonly prescribed?

A

not always available on the NHS

no solid evidence to suggest it has a better clinical outcome

125
Q

what is the difference between brands of levothyroxine?

A

differences in fillers and bulking agents between the various brands of tablets

= why some people prefer specific brands of levothyroxine over others when they are all structurally the same

126
Q

how does levothyroxine dose change when planning a pregnancy?

A

when planning = let doc know + have TFTs before

when pregnant = increased levothyroxine daily dose by 25-50mcg + then have regular TFTs

127
Q

what is the risk of complications in a pregnant woman with hypothyroidism?

A

even if thyroid levesl not ideal = risk of pregnancy complications only slightly higher

128
Q

who looks after patients with hypothyroidism?

A

GP and endocrinologist

129
Q

what happens in Hashimoto’s thyroiditis?

A

variant of hypothyroidism, caused by autoimmunity

thyroid gets infiltrated by white cells (lymphocytic infiltration) and slowly loses its function = usually enlarges but may not

130
Q

what are the two forms of autoimmune thyroidits?

A

Graves’ disease and Hashimoto’s thyroiditis

131
Q

differentiate between Graves’ disease and Hashimoto’s thyroiditis

A

Graves’ = autoimmune hyperthyroidism

Hashimoto’s = autoimmune hypothyroidism

132
Q

what are common triggers of Graves’ and Hashimoto’s?

A

stress factors

pregnancy

genetic predisposition

133
Q

why is Hashimoto’s disease frequently missed?

A

because of undue reliance on blood tests

= fT4 usually decrease but doesn’t have to
= TSH usually rises but may be normal or low

134
Q

which test conclusively helps diagnose Hashimoto’s and why?

A

antibody test

= any level of thyroid antibodies usually suggests an autoimmune process at work

135
Q

why may thyroid antibody levels decrease?

A

as the damage becomes chronic

136
Q

what causes hypometabolism in Hashimoto’s?

A

low thyroid function

137
Q

how does mild Hashimoto’s present clinically?

A

may be nothing obvious and only noticed during a general blood test

138
Q

what are the two ways Hashimoto’s can present?

A

goitrous autoimmune thyroiditis (enlarging of the thyroid gland)

atrophic autoimmune thyroiditis (shrinking of the thyroid gland)

139
Q

explain how goitrous autoimmune thyroidits can occur

A
  • progressive lymphocytic infiltration enlarges the thyroid
  • the gland itself becomes a mass of fibrous tissue
  • gland enlarges into goitre
140
Q

explain how atrophic autoimmune thyroidits can occur

A
  • antibodies block the TSH receptors in the thyroid and on the basis that what you don’t use, you lose, the glandular tissue shrinks
141
Q

what triggers goitrous autoimmune thyroidits?

A

lymphocytic infiltration of the of the glandular tissue

142
Q

what triggers atrophic autoimmune thyroidits?

A

antibodies block the TSH receptors in the thyroid

143
Q

differentiate between Hashimoto’s and hypothyroidism

A

Hashimoto’s = specifically autoimmune hypothyroidism

hypothyroidism = can have other causes besides autoimmune ones

(treatment same)

144
Q

what is the most common cause of hypothyroidism in the developed world?

a) subacute thyroiditis
b) Hashimoto’s thyroiditis
c) thyroidectomy
d) drugs
e) iodine deficiency

A

b) hashimoto’s thyroiditis

most common cause of primary hypothyroidism in the UK

145
Q

what is the most common cause of hypothyroidism in the developing world?

a) postpartum thyroiditis
b) Hashimoto’s thyroiditis
c) Graves’ disease
d) subacute thyroiditis (de Quervain’s)
e) iodine deficiency

A

e) iodine deficiency

iodine deficiency is the most common cause of hypothyroidism in the DEVELOPING world

146
Q

why does subclinical hypothyroidism present with raised TSH and normal fT4?

A

more TSH is needed to produce a normal level of thyroid hormone which is why TSH is slightly raised