Disability

Under the Equality Act 2010 you are disabled if you have a physical or mental impairment with a substantial and long-term adverse effect on your ability to carry out normal day-to-day activities. It is a legal test, not a medical label — and whether you meet it is the gateway every disability discrimination claim must pass through first.

What is the legal definition of disability?

Under s.6 of the Equality Act 2010, a physical or mental impairment with a substantial and long-term adverse effect on your ability to carry out normal day-to-day activities. Substantial means more than minor or trivial; long-term means it has lasted or is likely to last at least 12 months, or for the rest of your life.

Which conditions automatically count as disabilities?

Cancer, HIV infection and multiple sclerosis count as disabilities from the day of diagnosis, with no need to show any effect on daily life. Certified sight impairment also qualifies automatically. Beyond those, no condition is automatically in or out — the question is always the effect of the impairment on you.

Is depression or anxiety a disability under the Equality Act?

It can. Mental impairments qualify on the same test as physical ones: if depression, anxiety or another condition has a substantial, long-term adverse effect on normal day-to-day activities — sleep, concentration, social interaction, getting through a working day — it can meet the definition. Medical records showing duration and impact carry the weight.

Is stress a disability under the Equality Act?

Stress on its own is not usually treated as an impairment, but it can lead to one. A reaction to difficult circumstances at work is not in itself a disability; where it develops into a condition such as depression or anxiety with a substantial, long-term effect on day-to-day activities, that condition can meet the definition.

Is ADHD or autism a disability under the Equality Act?

They can be. Neither is automatically a disability, but ADHD, autism and other neurodivergent conditions meet the definition where their effect on day-to-day activities, such as concentration, communication or organising tasks, is substantial and long-term. Evidence of how the condition affects you, not just the diagnosis, is what decides it.

I manage my condition with medication. Am I still disabled in law?

Very possibly. The law generally judges the effect of your impairment as it would be without the medication or treatment — the deduced effect. If stopping your treatment would leave substantial effects on daily life, the definition can be met even though day to day you cope well. The main exception is poor eyesight corrected by glasses or contact lenses.

Do I have to tell my employer about my disability?

Usually there is no legal duty to tell your employer, but for some claims knowledge matters. The duty to make reasonable adjustments, and claims for discrimination arising from disability, depend on what the employer knew or ought reasonably to have known. Telling your employer in writing about your condition and its effects removes the argument entirely — and starts the duty running.

What conditions are excluded from the definition?

Regulations exclude some matters from counting as impairments in themselves, including addiction to alcohol or nicotine, hay fever, and certain tendencies. But conditions resulting from an excluded matter can still qualify — liver disease or depression arising from alcohol dependency, for example, are assessed on their own effects.

Employment Tribunal · Glossary

Last reviewed: August 2026

Employment Tribunal track

Under s.6 of the Equality Act 2010, a disability is a physical or mental impairment with a substantial and long-term — 12 months or more — adverse effect on normal day-to-day activities, with cancer, HIV and multiple sclerosis counting from diagnosis.

Where this comes from

Equality Act 2010, s.6 and Schedule 1

— the definition and its supplementary rules.

Equality Act 2010 (Disability) Regulations 2010

— exclusions and deemed cases.

Statutory guidance on the definition of disability

— what tribunals take into account when applying s.6.

The four elements, unpacked

Impairment covers physical and mental conditions alike, with no requirement for a formal diagnosis label — what matters is that something is wrong and its effects. Substantial is a low bar: more than minor or trivial. Long-term means the effect has lasted 12 months, is likely to last 12 months, or is likely to last the rest of your life — and a condition that fluctuates or recurs still counts if its substantial effect is likely to come back. Normal day-to-day activities are ordinary things: walking, concentrating, sleeping, lifting, interacting with people, getting through a shift — not feats like running marathons.

Two rules do quiet but decisive work. First, the effect of medical treatment is disregarded: if medication, therapy or an aid controls your condition, the tribunal asks what the effects would be without it — glasses and contact lenses being the main exception. Second, some conditions are deemed disabilities with no effects test at all: cancer, HIV infection and multiple sclerosis qualify from the day of diagnosis, as does certified sight impairment. Progressive conditions more generally qualify once they have some effect, provided a substantial effect is likely in future.

Why the definition is worth fighting over

1 It unlocks reasonable adjustments. The duty on employers to remove disadvantages — adjusted duties, equipment, hours, absence triggers — exists only for people who meet s.6. See reasonable adjustments.
2 It unlocks discrimination arising from disability. Dismissal or discipline for sickness absence, slowed performance or behaviour caused by the condition is only challengeable this way if the definition is met.
3 It shapes the whole case. Employers dispute disability status precisely because a successful challenge ends the claim before the merits are ever examined. Tribunals often decide it at a preliminary hearing.
4 Knowledge triggers duties. Adjustment and arising-from claims depend on what the employer knew or should have known. Telling your employer, in writing, about the condition and its effects starts that clock and closes that escape route.

How it works in practice

A payroll administrator has had depression for two years, managed with medication and therapy. Most days she functions well; without treatment she cannot sleep, concentrate or face other people. After a restructure doubles her workload she has repeated absences, and is dismissed for “unreliable attendance”. The employer argues she is not disabled because she “seemed fine”.

depression (2 years)

yes — over 12 months

effects judged without medication

s.6 met — claim proceeds to the merits

Her GP records document the diagnosis, the prescription history and the effects during relapses. The tribunal applies the deduced-effect rule, finds her disabled, and the case proceeds to whether dismissing for disability-related absence — without considering adjustments — can be justified. The “seemed fine” argument fails, as it usually does where the treatment rule applies.

Assuming a diagnosis settles it. Outside the deemed conditions, the label matters less than the evidence of effect: what you cannot do, or can only do with difficulty, and for how long. An impact statement plus medical records beats a diagnosis letter alone.
Underselling the effects out of pride. People describe their worst days as “fine” from habit. The tribunal needs the unvarnished picture, including what treatment masks — that is the legally relevant one.
Keeping the condition secret, then claiming adjustments. An employer that neither knew nor reasonably should have known may escape the adjustments duty. Disclosure in writing converts sympathy into obligation.
Missing that past disability counts. The Act protects people who had a disability. Treatment because of a past condition remains challengeable.
Confusing the definition with the claim. Meeting s.6 wins the gateway, not the case. The substantive claim — direct discrimination, harassment, adjustments, arising-from — still has to be proved on its own elements.

Frequently asked questions

Sources & further reading

Equality Act 2010, s.6 and Schedule 1 (legislation.gov.uk)
Equality Act 2010 (Disability) Regulations 2010 (legislation.gov.uk)
Guidance on matters to be taken into account in determining questions relating to the definition of disability — gov.uk
Definition of disability under the Equality Act 2010 — gov.uk
Disability discrimination — acas.org.uk

Unsure whether your condition meets the legal test?

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Last reviewed: August 2026.

References checked against the Equality Act 2010, Schedule 1 and the 2010 Disability Regulations as in force on 24 August 2026.

This page is explanatory only and is not legal advice. Start My Claim is self-service software, not a law firm — its tools help you build and run your own case.