What is Illness?

Peter D Toon is a retired GP and medical educator, with a longstanding interest in the philosophy of healthcare. His writings include RCGP occasional papers on the ethics and philosophy of general practice and can be found at www.peterdtoon.com

Everyone has things about themselves that they (or others) would like to be different,  Some are congenital, some acquired. Some are considered to be part of our character, our physique or our personality; others as sins, moral or physical weaknesses, or as illnesses. In certain circumstances terms synonyms for illness e.g.  ‘sickness’ or ‘mental disorder’¹ are used, but these have similar implications.  There is much debate in popular media about whether specific conditions are illnesses or not, and whether or how they should be treated.  I consider what light these debates throw on why we define a condition as illness rather than another type of problem, and the implications of this decision.

I argued previously that we should distinguish between between disease categories which are empirical statements, similar to biological taxonomy, and illness, which is an evaluative judgement that a condition is undesirable.² A few disease categories are not evaluated as illnesses,²  but since they are tools devised by health professionals most disease categories are negatively evaluated as illnesses. Consequently Hume’s famous facts/values confusion often appears here; terms like treatment, disorder, and abnormality, are fact/values portmanteaux; they look like factual statements, but they have an evaluative element.

Disputed physical Conditions

Some medical authorities suggest ‘bat ears’ should be ‘corrected’ (note the covert evaluation) because children with them may be bullied and teased,^3,4 but some people like them. The actor Russell Tovey delights in his: “Someone said to me, ‘If you want to make it in Hollywood, you’ve got to pin your ears back.’ And I remember being like, ‘They’re my trademark!’ I’ve never had an issue with my ears.”⁵ Fans like them too.⁶  Similarly people with other unusual physical features such as intersex⁷ increasingly reject negative evaluation of their condition.

One way bat ears can be ‘corrected’ is by cosmetic surgery. Similarly nasal features, which can be categorised objectively;  tip irregularity/asymmetry, a crooked middle-third of the nose, or a dorsal hump; are evaluated as ‘aesthetic abnormalities’ ‘correctable’ by plastic surgery.⁸  Generally the UK NHS has not funded these treatments,⁹ making an implicit distinction between needs (reshaping a hare-lip) and wants (reshaping a big nose).

Being abnormal

These examples illustrate that conditions are often seen as illnesses because they deviate from a norm. This norm may be an ideal of what human beings should be like, so that anything too different is considered abnormal. Youth may be seen as part of being normal, so cosmetic surgery is used to reverse the effects of ageing. Hormone Replacement (HRT) to counteract the effects of lower post-menopausal oestrogen levels is similarly justified, providing ‘additional energy and sense of well-being, almost like a fountain of youth’ .¹⁰ One HRT pioneer described the menopause as a deficiency state analogous to myxoedema, implying that all post-menopausal women should have HRT.¹¹  Or the norm may be statistical, as with ear protrusion, which is a continuous variable. Those at both extremes are statistically abnormal, but we ‘treat’ only one tail of the distribution;  we don’t make very flat ears stick out more.

Psychological Conditions

I’ve started with physical conditions because the issue is the boundaries of illness, not the status of mental illness, but most disputed conditions are psychological, and disputed physical conditions (bat ears, big noses,) are usually treated medically for psychological not physiological reasons. Controversial psychological conditions include aspects of sexuality, neuro-atypical conditions (e.g. Asperger’s syndrome, ADHD and dyslexia), depression, and addictions.

As with physical conditions, sometimes the dispute is whether these are problems or merely a different way of being human. Over the last century male homosexuality has been categorised as a crime, a sin, an illness, or part of normal human variation accepted by Equal Marriage Acts.  Recently people with Asperger’s syndrome have argued similarly that their mode of mental functioning has benefits as well as drawbacks,¹² and is a disability only because society makes it so.

Where to draw the line?

For some depression is a severe, life-threatening condition¹³ which few would argue should not be treated medically, but there is a continuum between this major depression and normal sadness. Everyone has days when they feel less cheerful, and some have more than others. It would be strange not to feel sad after the death of a close friend or relative or the end of a relationship. Views on where on this continuum the boundary of illness should be drawn have changed. In the 1990s UK GPs were criticised for ‘missing depression’,¹⁴ whilst twenty years later they were ‘medicalising unhappiness’.¹⁵

One possible reason for this change was the advent of safer drugs with fewer unwanted effects than previous treatments,¹⁶  making doctors more willing to prescribe and patients more willing to take medication;  both perhaps encouraged by vigorous advertising, sometimes criticised as  ‘disease-mongering’.

Secondary gain as primary purpose

Defining a condition as an illness implies that it is outside our control, making it socially acceptable (apart from a few stigmatised conditions). If it prevents us working or fulfilling social obligations that’s not our fault. Clinicians issue certificates excusing people from work or other responsibilities on the grounds of illness.¹⁷ Sometimes illness excuses acts as well as omissions, varying from angry words due to a headache to diminished responsibility as a defence against homicide.¹⁸ Sometimes it entitles us to benefits in cash¹⁹ or in kind.²⁰

Often this seems reasonable. We generally do not choose to break an arm or have a heart attack,  so although we do have some control over the risk of these events, generally it seems fair that we should not be blamed for what they prevent us doing, and be supported if they stop us working. But sometimes avoiding responsibility or obtaining benefits seems to the main reason for defining a condition as an illness.

For example is a promiscuous President condemned as a sexual predator or excused as a ‘sex addict’?²¹  Is dyslexia as some suggest a socially acceptable excuse for lack of intellectual ability; ‘a pretentious word for thick’?²²  Empirical data shows that dyslexia can be distinguished from general lack of intellectual ability, but does this mean it should be evaluated differently,  and if so when? People with dyslexia get special arrangements in examinations,²³ but what is a ‘reasonable adjustment’? Should proof-readers be excused mistakes because they are dyslexic, or is this a step towards the ‘generalised incompetence disorder’  which excuses all errors in the fictional ‘Medocracy of Gelbetia?’²⁴

ADHD raises similar issues.  Children who could not sit still,  pay attention in class or acted without thinking were seen as ‘naughty’ until scientists found a difference in their brain chemistry, and developed drugs which made these children behave ‘more normally’ (another fact/value portmanteau).  Some politically right-wing commentators suggest this is medicalisation of bad behaviour,²⁵ whilst others criticise the increased use of ADHD drugs as  ‘disease mongering’.²⁶

Taking emotional support animals (ESA)  on airlines raises similar issues. If guide dogs for blind people can fly at no extra charge, why not dogs which help people deal with anxiety, phobias, or depression?  Between 2002 and 2019 the number of ESA certificates issued rose twelvefold, and some suggested that people obtained them to avoid paying for their pet’s flights, or so they could travel in the cabin rather than in the hold.²⁷

 Substance Addictions

There is no argument that substance addictions are undesirable;  the debate is rather whether they should be seen as illness, sin, or crime.  There is a genetic predisposition,²⁸ presumably related to brain biochemistry, so biomedical treatment seems reasonable, although in practice drugs play a small part in treatment and psychological approaches seem more effective.²⁹  But another approach to addiction is Alcoholics Anonymous’s 12 step programme,  based on taking responsibility, acknowledging one’s faults, one’s powerlessness and seeking help “from a higher power”;³⁰ a paradigm of sin and repentance rather than illness. Also possessing some addictive drugs is a crime.¹ Thus someone with an addiction may be treated as being ill, attend a group drawing on theological ideas, or be punished as a criminal.

Conclusions

So what can we learn from looking at these controversial conditions?

Our view of what constitutes an illness is socially determined and based on value judgements, not on scientific facts. Mayes summarised this clearly regarding ADHD: “…where the boundary between ADHD and typical childhood behaviour is located is ultimately a political and social choice, not a scientific one. No amount of scientific research can resolve this question for us.”³¹ The same applies to all the conditions discussed above and indeed to all illnesses,  although in most cases society is not divided.

It follows that whilst clinicians have expertise in placing a situation into a diagnostic category and hence what medical or psychological treatments are relevant, they have no particular expertise in deciding whether that condition is an illness or whether treatment is appropriate.

Clinicians need to be aware that healthcare can be used to reinforce oppressive social norms. Gross examples like Nazi eugenics and Soviet psychiatry are easy to spot, but less obvious cases may be not be questioned, particularly if the person with the condition wants it changed because they have internalised the negative social view of their condition.³²

Finally society needs to distinguish four issues:

1. Can biomedical intervention change a situation?
2. Is that change desirable?
3. Is the individual responsible for the situation?
4. What excusing and benefits are appropriate?

Although often related, these issues are not logically independent. Assuming they are can lead to inappropriate practices.¹⁷

References

1. Sentencing Council, Drug offences, https://www.sentencingcouncil.org.uk/outlines/drug-offences/accessed 27/3/25
2. Toon PD,  Defining disease–classification must be distinguished from evaluation. J Med Ethics. 1981 Dec;7(4):197-201.
3. Lloyd MS, Otoplasty for prominent ears, https://www.marksheldonlloyd.com/procedures/ears/otoplasty-prominent-ears-that-stick-out  accessed 27/3/25
4. NHS,  Prominent ears/bat ears/pinnaplasty – patient information. https://www.wsh.nhs.uk/CMS-Documents/Patient-leaflets/ENT/6139-1-Pinnaplasty.pdf accessed 27/3/25
5. Just Jared Staff, Russell Tovey Talks About His ‘Trademark’ Ears, Explains Why He Came Out Early in His Career Nov 11, 2022 https://www.justjared.com/2022/11/11/russell-tovey-talks-about-his-trademark-ears-explains-why-he-came-out-early-in-his-career/ accessed 27/3/25
6. O’’Connor L   Russell Tovey’s Ear Obsession Takes the Internet by Storm  April 1, 2024 https://thepinktimes.com/russell-toveys-ear-obsession-takes-the-internet-by-storm/ accessed 27/3/25
7. NBC News (2021) Intersex people have been challenging ‘gender-normalizing surgery.’ Doctors are starting to listen. https://www.nbcnews.com/nbc-out/out-health-and-wellness/intersex-people-challenging-gender-normalizing-surgery-doctors-are-sta-rcna3815 accessed 27/3/25
8. Alharethy, S  Aldrees T, Aljrid R, Alanazi A,. Algaryan SK & Jange YJ Common nasal deformities among rhinoplasty patients in a university hospital in Saudi Arabia, Ann Saudi Med. 2017 May-Jun; 37(3): 207–211. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6150583/
9. NHS, (2023) Is cosmetic surgery available on the NHS?  https://www.nhs.uk/conditions/cosmetic-procedures/advice/cosmetic-procedures-on-the-nhs/ accessed 27/3/25
10. Renue Pharmacy (2017) Is Hormone Replacement Therapy The Fountain of Youth? https://renuerx.com/general-health/is-hormone-replacement-therapy-the-fountain-of-youth/ accessed 27/3/25
11. The late Professor John Studd (personal communication). He also gave interviews in the public media such as this article in The Times https://www.thetimes.com/travel/destinations/uk-travel/england/london-travel/feeling-hormonal-8bkfmrvgb6m [accessed 27/3/25]
12. University of Cambridge (2015), Is Asperger Syndrome a disability? https://www.cam.ac.uk/news/is-asperger-syndrome-a-disability accessed 27/3/25
13. Hong Cai, H,  Xie X,  Zhang Q, Cui X,, Lin J X,  Sim K et al Prevalence of Suicidality in Major Depressive Disorder: A Systematic Review and Meta-Analysis of Comparative Studies, Front Psychiatry. 2021; 12: 690130. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8481605/
14. Paykel ES, Priest RG. Recognition and management of depression in general practice: consensus statement. British Medical Journal 1992; 305(6863): 1198, www.bmj.com/content/305/6863/1198
15. Parker G. Is depression overdiagnosed? Yes. British Medical Journal 2007; 335: 328, www.bmj.com/content/335/7615/328
16. Steffens DC,  Krishnan KR, and  Helms MJ. Are SSRIs better than TCAs? Comparison of SSRIs and TCAs: a meta-analysis    1997.Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet]: Centre for Reviews and Dissemination York (UK) https://www.ncbi.nlm.nih.gov/books/NBK67142/
17. Toon PD,  Practice Pointer. “I need a note, doctor”: dealing with requests for medical reports about patients.  BMJ. 2009 Feb 3;338:b175.
18. Sentencing Council UK, Manslaughter by reason of diminished responsibility, Common law, Homicide Act 1957, s.2   Guideline effective from: 01 November 2018 https://www.sentencingcouncil.org.uk/offences/crown-court/item/manslaughter-by-reason-of-diminished-responsibility/
19. UK Government, Statutory sick pay (SSP) https://www.gov.uk/statutory-sick-pay accessed 27/3/25
20. UK Government Dept of Transport , Guidance  – Who can get a Blue Badge? (Updated 10 August 2021) https://www.gov.uk/government/publications/blue-badge-can-i-get-one/can-i-get-a-blue-badge accessed 27/3/25
21. Kaminer W, Is Clinton a Sex Addict? March 22, 1998 https://slate.com/news-and-politics/1998/03/is-clinton-a-sex-addict.html accessed 27/3/25
22. Liddle  R Dyslexia is meaningless. But don’t worry – so is ADHD How many illnesses of modern childhood are excuses for bad behaviour, stupidity or parental neurosis? Spectator, 15 March 2014, https://www.spectator.co.uk/article/dyslexia-is-meaningless-but-don-t-worry-so-is-adhd/ accessed 27/3/25
23. British Dyslexia Association, Exam access arrangements,  https://www.bdadyslexia.org.uk/advice/children/my-childs-education/exam-access-arrangements accessed 27/3/25
24. Dare B, Brian Gulliver’s travels,  Series 1 Episode I, Gelbetia, https://www.comedy.co.uk/radio/brian_gullivers_travels/episodes/1/ accessed 27/3/25
25. Birchill J, Why I’m sceptical of the ADHD epidemic, Spectator, 5 February 2023, https://www.spectator.co.uk/article/why-im-sceptical-of-the-adhd-epidemic/ accessed 27/3/25 
26. Isaacs D. Disease mongering. J Paediatr Child Health. 2013 Jul;49(7):509-10. doi: 10.1111/jpc.12270. PMID: 23841543. https://onlinelibrary.wiley.com/doi/pdf/10.1111/jpc.12270 accessed 27/3/25
27. Wunderman  A, Counterfeit canines: the air travellers with fake service dogs, Guardian, London Wed 16 Feb 2022 10.00 GMT, https://www.theguardian.com/lifeandstyle/2022/feb/16/fake-service-dogs-emotional-support-animals-airplanes accessed 27/3/25
28. Ducci F & Goldman D, The Genetic Basis of Addictive Disorders, Psychiatr Clin North Am. 2012 Jun; 35(2): 495–519.
29. Clinical Guidelines on Drug Misuse and Dependence Independent Expert Working Group,  Drug misuse and dependence UK guidelines on clinical management, UK Dept of Heath 2017, https://assets.publishing.service.gov.uk/media/5a821e3340f0b62305b92945/clinical_guidelines_2017.pdf  accessed 27/3/25 
30. Alcoholics Anonymous UK The 12 Step programme. https://www.alcoholics-anonymous.org.uk/about-aa/what-is-aa/12-steps/ accessed 27/3/25 
31. Mayes R, ADHD, or the Medicalization of Social Problems (Review), Am J Public Health 2019 September; 109(9): 1154–1155 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6687270/
32. Mason M, Internalized Oppression, in Reiser, R. and Mason, M. (eds) (1990) Disability Equality in Education, London: ILEA https://disability-studies.leeds.ac.uk/wp-content/uploads/sites/40/library/Mason-Michelene-mason.pdf  accessed 27/3/25 

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