Tiredness

Feeling tired all the time is such a common presenting symptom that ‘TATT’ has become a universal acronym. In around 85% of first consultations the cause is apparent by the end. Although the vast majority turn out to have a non-organic cause, it is clearly important not to get lulled into ignoring important physical illness. A structured approach makes for a successful consultation.

Published: 2nd August 2022 | Updated: 3rd February 2023

Differential diagnosis

Common Diagnoses

  • True Depressive Illness
  • Stress (Overwork, Young Children, Boredom, etc.)
  • Anaemia
  • Acute Post-Viral Fatigue
  • Hypothyroidism

Occasional Diagnoses

  • Diabetes Mellitus
  • Sleep Apnoea (Though Usually Presents with Sleepiness Rather than Tiredness)
  • Iron Deficiency (in the Absence of Anaemia)
  • Coeliac Disease
  • Any Cause of Insomnia
  • Chronic Post-Viral Fatigue Syndrome (‘ME’)
  • Major Organ Failure (Heart, Liver, Kidney)
  • Hyperthyroidism
  • Substance Misuse
  • Drug Therapy (Β-Blockers, Diuretics)

Rare Diagnoses

  • Malignant Disease
  • Chronic Infection (e.g. Tb, Hepatitis, HIV, Lyme Disease)
  • Chronic Neurological Disorders (Parkinson’s Disease, Myasthenia Gravis, MS, Motor Neurone Disease)
  • Other Endocrine Disorders and Deficiency States (e.g. Addison’s Disease, Hypo- or Hypercalcaemia, Hyponatraemia, Hypokalaemia)
  • Connective Tissue Diseases (RA, Polymyalgia Rheumatica [PMR], SLE)
  • Carbon Monoxide Poisoning
  • Postural tachycardia syndrome (PoTS)

Ready reckoner

Key distinguishing features of the most common diagnoses

DepressionStressAnaemiaPost-ViralHypothyroidism
Diurnal VariationYesPossibleNoNoNo
Identifiable Life Event TriggersPossibleYesNoNoNo
Recent IllnessPossiblePossiblePossibleYesNo
Mucosal/Nailbed PallorNoNoYesNoPossible
Cold, Dry SkinNoNoPossibleNoYes

Possible investigations

Likely: Urinalysis, FBC, blood glucose or HbA1c, TFT.

Possible: ESR/CRP, U&E, LFT, ferritin, calcium, anti-endomysial and anti-gliadin antibodies.

Small Print: CXR, autoantibody screen, sleep studies, further blood tests as indicated such as HIV, glandular fever test, hepatitis or Lyme disease serology, Tilt table test.

  • Urinalysis: Simple screen for diabetes and renal disease.
  • Blood glucose or HbA1c: For diabetes.
  • TFT for hypo- or hyperthyroidism.
  • FBC: The anaemias, infection and alcohol abuse.
  • ESR/CRP: Raised in a host of causes; not diagnostic but suggests a possible underlying physical cause.
  • U&E: Deranged in renal failure, hyponatraemia, hypokalaemia and Addison’s disease.
  • LFT: For liver disease (malignancy, alcohol abuse and hepatitis).
  • Ferritin: Iron deficiency may cause tiredness in the absence of anaemia.
  • Calcium: Hyper- or hypocalcaemia may cause tiredness.
  • Anti-endomysial and anti-gliadin antibodies: Will suggest a diagnosis of coeliac disease.
  • Autoantibody screen: For connective tissue disease.
  • Sleep studies: To explore the possibility of sleep apnoea.
  • Further blood tests: These will be dictated by the clinical picture and might include HIV, glandular fever or hepatitis or Lyme disease testing.
  • CXR: May reveal malignancy, cardiac failure or TB.
  • Tilt table test: if suspicion of PoTS

Top Tips

  • Tiredness as a presenting symptom, in the absence of other significant volunteered symptoms – particularly weight loss or gain – is unlikely to have a physical cause.
  • The longer tiredness has been a problem, the less likely you will find any remediable cause.
  • Make eye contact with the patient and possibly shake hands – your first impressions as to whether or not the patient is actually ‘ill’ are likely to prove correct, and may give early clues to easily overlooked causes such as Parkinson’s disease.
  • If you suspect depression, enquire directly about relevant symptoms – you do not have to ‘exclude’ physical illness before making a presumptive diagnosis of this sort.
  • Investigations ordered are often more therapeutic than diagnostic.
  • Ask about other household members’ health and well-being. Carbon monoxide poisoning would be likely to affect them too.
  • Do not be over zealous for the usual ‘blood screen’. Often patients ‘promised’ blood tests if their symptoms persist do not return. Also, checking blood quite often raises irrelevant abnormalities that concern the patient and confuse the issue.

Red Flags

  • Take tiredness associated with weight loss seriously – this combination suggests malignant disease or hyperthyroidism.
  • Don’t miss depressive illness by being coy in enquiry or colluding with patient denial.
  • Don’t miss easy-to-find signs when physical illness seems a real possibility – check pulse rate, mucous membranes for pallor, lymph nodes, chest and abdomen.
  • Consider a rare cause if the symptoms progress and the patient starts to look unwell.
  • Beware the very rare attender. Although the overall pick-up rate for significant physical disease is low when tiredness is presented in the absence of other significant symptoms, this does not hold for rare attenders, in whom any symptom, no matter how vague, should be taken very seriously.
Report errors, or incorrect content by clicking here.
Website disclaimer

Nursing in Practice Reference is based on the best-selling book Symptom Sorter.

The experts behind Nursing in Practice Reference are Marilyn Eveleigh who is Nursing in Practice’s editorial advisor and a primary care nurse in East Sussex, Dr Keith Hopcroft who is the co-author of Symptom Sorter, a GP in Essex and Pulse editorial advisor and Dr Poppy Freeman, a GP in Camden and also a clinical advisor to Pulse.

For use by healthcare professionals only, working within their scope of professional practice. Nursing in Practice Reference is for clinical guidance only and cannot give definitive diagnostic information. Appropriate referrals should be made following individual practices protocols and employer expectations, locally agreed pathways and national guidelines.