The legal definition of disability is broader than most people expect. Many workers who would describe themselves as disabled don’t realise they have legal protection, and many who wouldn’t use the word “disabled” about themselves do.
Understanding whether the law covers your situation is the essential first step.
The Equality Act 2010 definition
Under the Equality Act 2010, you are disabled for legal purposes if you have a physical or mental impairment that has a substantial and long-term adverse effect on your ability to carry out normal day-to-day activities.
There are four parts to that definition, and all four need to be met:
A physical or mental impairment This covers a very wide range of conditions, physical health conditions, mental health conditions, sensory impairments, learning disabilities, neurodivergent conditions, and more. There is no list of qualifying conditions. What matters is whether you have an impairment, not what it is called.
Substantial Substantial means more than minor or trivial. It does not mean severe or significant. If your impairment has a noticeable effect on what you can do, it is likely to meet this threshold, particularly once you take into account what the law says about how the effect is measured (see below).
Long-term Long-term means the impairment has lasted, or is likely to last, at least twelve months, or for the rest of your life. An impairment that comes and goes in episodes can still be long-term if the underlying condition has lasted twelve months or more.
Adverse effect on normal day-to-day activities Day-to-day activities include things like concentration, memory, mobility, communication, managing relationships, and the ability to carry out tasks at work. The question is not whether you can manage day to day activities at all, it is whether there is an more than minor or trivia adverse effect.
What the law ignores:
coping mechanisms and medication
This is one of the most important things to understand about how the definition works.
When deciding whether your impairment has a substantial adverse effect, the law requires that any measures you take to manage or reduce its impact are disregarded. This includes medication, aids and equipment, coping strategies, and adjustments you have already put in place yourself.
In practice, this means: if you take medication that controls your symptoms, the question is not how you are with the medication or treatment, but how you would be without it. If you have developed ways of managing your condition that reduce its visible impact, those are set aside too.
Many people who feel they are “managing fine” turn out to have substantial adverse effects once this principle is applied.
The one exception is spectacles and contact lenses, which are not disregarded.
Progressive conditions
If you have a condition that is likely to get worse over time, such as Parkinson’s disease, motor neurone disease, you are protected under the Equality Act from the point of diagnosis, even if the condition does not yet have a substantial adverse effect on day-to-day activities.
Cancer, HIV, and multiple sclerosis are automatically deemed disabilities from the point of diagnosis, without needing to meet the substantial and long-term test.
Recurring and fluctuating conditions
Conditions that come and go, such as depression, epilepsy, Crohn’s disease, fibromyalgia, or many forms of chronic pain, can still meet the definition. The law looks at the overall picture of the condition over time, not just how you are on a good day.
If your condition has periods of remission but the underlying impairment has lasted or is likely to last twelve months, it is likely to qualify.
Mental health conditions
Mental health conditions are covered by the same definition as physical conditions. Depression, anxiety disorders, PTSD, bipolar disorder, OCD, eating disorders, and psychotic conditions can all qualify as disabilities under the Equality Act, often more readily than people assume.
There is no requirement that a mental health condition be severe or that you have been hospitalised or unable to work. What matters is whether the effect on day-to-day activities is more than minor or trivial.
Neurodivergent conditions
ADHD, autism, dyslexia, dyspraxia, dyscalculia, and other neurodivergent conditions are frequently covered by the Equality Act 2010. The effects on concentration, communication, processing, memory, and organisation can all constitute adverse effects on day-to-day activities.
Many neurodivergent workers are told, or assume, that their condition does not qualify, particularly if they are considered “high-functioning” or have developed coping mechanisms. The principle of disregarding coping mechanisms (see above) is especially important here.
You do not need a formal diagnosis
There is no legal requirement to have a formal diagnosis in order to be protected under the Equality Act. If your impairment has a substantial and long-term adverse effect on your day-to-day activities, you may be protected, even if you are still waiting for a diagnosis, or have never sought one.
In practice, having medical evidence will strengthen your position if a dispute arises. But the absence of a diagnosis does not mean the absence of legal protection.
You do not need your employer to accept that you are disabled
Your employer does not determine whether you are disabled under the law. They may dispute it. A Tribunal may ultimately have to decide. But whether you qualify is a matter of law and evidence, not your employer’s opinion.
If your employer refuses to make adjustments or treats you less favourably on the basis that they do not consider you disabled, that refusal may itself be part of the unlawful treatment.
→ Next: What rights do disabled workers have?
This page provides legal information, not legal advice. It reflects the law in England, Scotland, and Wales.