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