Tiredness Flashcards
What is the difference between tiredness and fatigue?
Tiredness can often be relieved by sleep and rest
Fatigue is when the tiredness is overwhelming and is not relieved by sleep or rest
What are the 3 main types of causes of tiredness?
Psychological causes
Physical causes
Lifestyle causes
What is more common, physical or psychological causes of tiredness?
Psychological
How do psychological causes lead to tiredness?
Most psychological causes lead to poor sleep or insomnia, both of which cause daytime tiredness
Give examples for psychological causes of tiredness
Stress
Emotional shock
Depression
Anxiety
Give examples for physical causes of tiredness
Iron deficiency anaemia/ iron deficiency without anaemia
Hypothyroidism
Sleep apnoea
Insomnia
Coeliac disease
Chronic fatigue syndrome
EBV
Influenza
Diabetes
Restless legs
Pregnancy (particularly in the first 12 weeks)
Obesity
Being underweight (poor muscle strength)
Cancer treatment (chemo, radio)
Side effects of medicines/ some herbal remedies
Carbon monoxide poisoning
What are some lifestyle causes of tiredness
Alcohol (stick to 14 units weekly)
Drug dependence
Caffeine
Exercise (too much/ too little)
Night shifts
Daytime naps
Roughly what percentage of GP consultations are due to fatigue?
7%
What percentage of patients with fatigue receive a diagnosis?
approx. 66%
What percentage of patients with fatigue receive a diagnosis through blood tests?
<10%
What are some common red flag diagnoses for tiredness?
Depression
Chronic Heart Failure
Diabetes Mellitus
COVID-19
HIV infection
Acute myocardial ischaemia
Atrial fibrillation
COPD
Tuberculosis
Stroke
Uncommon red flag diagnoses for tiredness
Addison’s disease
Chronic myeloid leukaemia
Hodgkin’s lymphoma
Primary biliary cirrhosis
Underlying malignancy (non-lymphoma)
How can you classify tiredness in fatigue?
Frequency (common-uncommon)
Consequence (serious-less serious)
Draw out the hypothalamic-pituitary-thyroid axis
Causes of primary hypothyroidism?
Iodine deficiency - lack of Thyroxine production
Hashimoto’s - Antibodies against TSH receptors therefore no TSH effect on thyroid and so lack of thyroxine production
Viral thyroiditis - due to viral infection, hypo-thyr. is the last stage of this infection and occurs whilst body is resolving infection
Congenital - hypoplastic
Thyroidectomy - lack of follicular cells
Cancer treatments - radiotherapy induced destruction of thyroid gland cells
Causes of secondary hypothyroidism?
Pituitary adenoma - impaired blood flow to normal tissue/ compression of normal tissue so less TSH secreted
Craniopharyngioma - progressive loss of production of some or all of pituitary hormones such as TSH
Sheehan’s syndrome - ischaemic necrosis of pituitary gland therefore hypopituitarism and lack of TSH secretion
Iron overload - Iron causes injury to thyroid followed by development of anti thyroid antibodies and hypothyroidism
Sarcoidosis - thyroid antibody positive in 20-30% of patients with extensive infiltration by epithelioid granulomas
Most common autoimmune cause of hypothyroidism?
Hashimoto’s
What does the Antigen Presenting Cell mistake for a foreign antigen in Hashimoto’s Hypothyroidism?
TPO is picked up as an antigen by Antigen Presenting Cell
What does the APC do after it recognises the ‘foreign’ antigen?
Antigen Presenting Cell presents MHC II to the T cell’s
What is the difference in how endogenous and exogenous antigens are recognised in the body?
Endogenous antigens presented by MHC I on the Cytotoxic T cells
Exogenous antigens floating around are ingested by professional APC and then presented by MHC II
What is the co-stimulation required for the T cell to be activated?
APC presents B7 to the T cell’s CD28 as the T cell needs co-stimulation from both the B7 and MHC II
What does the T-cell’s TCR then bind to in the B cell?
MHC II
- What is the co-stimulation required by the B cell to become activated?
B cell also needs co-stimulation from the T cell’s CD40 onto it’s CD40L
What is the resultant autoantibody that leads to thyroid damage?
Anti-TPO antibodies attack the thyroid gland’s TPO
What is the purpose of eosinophils?
Eosinophils attack viral, parasitic and bacterial infection
Which cells are innate cells in the immune system?
Eosinophil, Basophil, Neutrophil, Macrophage, Dendritic cell
Why do the innate cells not attack host cells?
Innate cells → Very fast and so they detect molecular patterns on the cell surface of the host cells such as PAMPs (peptidoglycan, lipopolysaccharides, lipoteichoic acid, mannan, flagella proteins)
Host cells, physiologically do not release these and so there is no attack on them
What stops the B cells and T cells from attacking the host cells?
B cells and T cells → AIRE expresses many genes in the body so it is possible for the thymus or bone marrow to produce a variety of antigens through mixing combinations of genes which the B and T cells interact with during development and if they are autoimmune then they are destroyed (central tolerance)
They are released into the circulation if they did not react with any of the host cell antigens replicated by AIRE
Treg cells are responsible for suppressing this autoimmunity and destroying them (peripheral tolerance)
What stops the Natural Killer cells from attacking the host cells?
NK cells → Inhibitory receptor on the NK cell as well as a stimulatory receptor
The stimulatory receptor binds to the stimulatory ligand of the host/foreign cell
The inhibitory receptor binds to the self-MHC I which is present on all nucleated (host) cells
If both receptors are bound, then the NK cell does not react which should be good as all host cells have the MHC I
Foreign cells or abnormal host cells will not usually have self-MHC I and so the NK cell has nothing to inhibit it from killing the cell
What medications/treatment can cause an under active thyroid?
- Radioactive iodine treatment, or surgery, to correct hyperthyroidism or to treat thyroid cancer
- Antithyroid drugs if given for an overactive thyroid disorder in too large a dose
- Medicines such as lithium (used for certain mental health problems) and amiodarone (used for
particular heart problems). - Some cough medicines containing large amounts of iodine can also interfere with the way the
thyroid functions - Some health foods taken in excess, e.g. kelp (seaweed)
- A malfunction of the pituitary gland (a gland in the brain that regulates the thyroid hormones)
- Radiation for head and neck cancers (not common in the UK)
Congenital: in some babies, thyroid does not develop/ doesn’t form thyroid hormones properly
What are the symptoms of hypothyroidism?
fatigue and tiredness
increased awareness of the cold
dry and coarse skin
hoarse or croaky voice
constipation
muscle weakness, cramps and aches
pins and needles in the fingers and hands (carpal tunnel syndrome)
heavier and longer periods
fertility problems
low libido
weight gain
puffy face and bags under the eyes
slow speech, movements and thoughts
memory problems
difficulty in concentration
slow heart beat
slightly raised blood pressure
raised cholesterol
slowed growth (in children)
After a few months or years untreated:
Dry flaky skin
Put on weight even though not eating more food than usual
Hoarse voice
Feel sluggish and find it difficult to think clearly
dry and thinning hair
low mood or depression
What proportion of tiredness symptoms resolve within 4 weeks?
3/4
2/3 of tiredness episodes are triggered by what?
Life stresses
Three types of tiredness?
Drowsiness
Shortness of breath
Weakness
Is exertional tiredness more likely to be physical or mental?
Physical - ‘I feel ok when I wake up, but it gets worse as I do things’ - this is worrying
What are some of the red flag symptoms associated with tiredness?
Specific malignancy features - focus on lung, breast, colon, upper GI and gynae
Weight loss - Thyroid, Coeliac disease
Infective symptoms - TB, Glandular fever, Lyme
Lymphadenopathy
Focal neurology - stroke
Joint pains - rheumatoid arthritis
Give 5 examples of psychological triggers for tiredness
Money
Family
Work
Drugs and Alcohol
Mood