What Are Major Bodily Functions Under the ADA?

Under the Americans with Disabilities Act, the operation of a major bodily function counts as a “major life activity,” so an impairment that disrupts one of these internal systems can qualify as a disability on its own. Major bodily functions under the ADA include immune response, normal cell growth, digestion, bowel and bladder function, endocrine and reproductive function, circulation, respiration, neurological and brain function, and the operation of the hemic, lymphatic, and musculoskeletal systems.¹ That framing matters because it protects people whose conditions are invisible from the outside: someone with Crohn’s disease, diabetes, or kidney failure has the same legal standing as someone who uses a wheelchair.

Which Bodily Functions Count

Federal regulations list the recognized systems, and the list is open-ended — it uses the phrase “including but not limited to.” The recognized functions and typical conditions they cover:

Immune system: HIV/AIDS, lupus, and other autoimmune disorders.
Normal cell growth: cancer and other conditions involving abnormal cell behavior.
Digestive and bowel functions: Crohn’s disease, irritable bowel syndrome, celiac disease, and chronic gastrointestinal disorders.
Bladder and genitourinary functions: kidney disease, interstitial cystitis, and related conditions.
Endocrine function: diabetes, thyroid disorders, and other hormonal conditions.
Circulatory and cardiovascular functions: heart disease, hypertension, and circulation disorders.
Respiratory function: asthma, COPD, and other breathing conditions.
Neurological and brain functions: epilepsy, multiple sclerosis, traumatic brain injuries, and conditions affecting cognition or motor control.
Hemic and lymphatic functions: sickle cell disease, hemophilia, lymphoma, and similar blood or lymph conditions.
Musculoskeletal function: severe arthritis, muscular dystrophy, and other conditions affecting bones, joints, and connective tissue.
Reproductive function: infertility and other conditions affecting reproductive biology.
Special sense organs and skin: vision, hearing, smell, taste, and skin disorders such as severe psoriasis or eczema.

Individual organs count too, not just entire body systems. A condition affecting a single kidney or one lobe of the liver qualifies if it substantially limits that organ’s operation.¹

What “Substantially Limits” Actually Means

The phrase sounds strict, but federal regulations set the bar deliberately low. An impairment does not have to prevent or severely restrict a bodily function to qualify.² The comparison point is the general population: you need to show that your body’s function is meaningfully limited compared with how most people’s bodies work.

The regulations also instruct that “substantially limits” be read as broadly as possible, favoring the individual seeking protection.² An impairment that limits one major life activity does not need to limit others. Someone whose endocrine system fails to regulate blood sugar has a qualifying impairment even if they can walk, see, and think without difficulty.³

Medication and Devices Don’t Disqualify You

This is where many people get tripped up, and where employers most frequently get the law wrong. When determining whether a bodily function is substantially limited, the analysis ignores the positive effects of treatment. If medication, medical devices, prosthetics, hearing aids, or assistive technology bring a condition under control, the law looks at the underlying impairment as if those measures did not exist.³

Someone with epilepsy whose seizures are controlled by medication still has an ADA disability, because without the medication the neurological impairment would substantially limit brain function. The same logic covers insulin for diabetes, inhalers for asthma, and immunosuppressants for autoimmune conditions. An employer cannot say “you seem fine, so you don’t qualify” when the reason you seem fine is that your treatment is working.

There is one exception. Ordinary eyeglasses and contact lenses do count in the analysis: if standard corrective lenses fully fix your vision, the law considers that correction when evaluating disability.³ Low-vision devices that magnify or enhance images do not fall under this exception.

Episodic Conditions and Conditions in Remission

Conditions that flare and die down are explicitly protected. An impairment that is episodic or in remission qualifies as a disability if it would substantially limit a major bodily function when active.³ The law evaluates the condition at its worst, not at the moment someone happens to be sitting in a doctor’s office.

Federal guidance identifies several conditions that commonly fit this pattern: epilepsy, hypertension, asthma, diabetes, major depressive disorder, bipolar disorder, and schizophrenia. Cancer in remission is the standard example — a condition that may not be actively limiting anything today but qualifies because of what it does when active.⁴

One Boundary: “Regarded As” Does Not Get Accommodations

The ADA also protects people who are treated as though they have an impairment, even when they do not. That path matters for discrimination claims: an employer who fires someone based on a perceived condition can still be liable. It does not, however, entitle a person to reasonable accommodations. Only the actual-impairment and record-of-impairment paths do.³ The “regarded as” path also does not apply to conditions that are both transitory (expected to last six months or less) and minor.

How to Request an Accommodation at Work

The ADA requires covered employers to provide reasonable accommodations unless doing so would cause undue hardship, meaning significant difficulty or expense relative to the employer’s resources.⁵ That obligation kicks in when you make a request.

The request does not need to be in writing, does not need to cite the ADA, and does not need to include the phrase “reasonable accommodation.” You just have to communicate that you need a change at work because of a medical condition. Once you do, the employer must engage in what federal guidance calls an interactive process: an informal back-and-forth to figure out what you need and what will work.⁶

If your condition and need are not obvious, the employer can ask for medical documentation. They are entitled to confirmation that you have an ADA-qualifying disability and that it creates a need for the accommodation you asked for. They are not entitled to your complete medical records, and they cannot request information about unrelated conditions.⁶ Documentation can come from a range of professionals: doctors, psychologists, physical therapists, or licensed mental health providers, depending on the condition.

An employer who ignores the request, refuses to engage, or delays without cause can face liability for failure to accommodate. The EEOC has said that unnecessary foot-dragging on an accommodation request can itself violate the ADA.⁶

Filing Deadlines and Damage Caps If Discrimination Happens

If an employer discriminates against you based on a condition affecting a major bodily function, the clock starts immediately. You generally have 180 calendar days from the discriminatory act to file a charge with the EEOC. That deadline extends to 300 days if your state has its own agency that enforces disability discrimination laws, and most states do.⁷ Filing is free.

These deadlines are not paused while you pursue internal grievances, union procedures, or mediation. Weekends and holidays count toward the total, though if the deadline lands on a weekend or holiday, you get until the next business day.⁷ If the EEOC does not resolve the matter, it issues a right-to-sue letter. You then have 90 days to file a lawsuit in federal court, and courts enforce that deadline strictly.

Federal law caps the combined compensatory and punitive damages you can recover for intentional discrimination, and the cap depends on the employer’s size:⁸

15 to 100 employees: $50,000
101 to 200 employees: $100,000
201 to 500 employees: $200,000
More than 500 employees: $300,000

The caps apply only to compensatory and punitive damages. Back pay, front pay, and attorney’s fees are separate and are not subject to these limits.⁹ Congress set these amounts in 1991 and has not adjusted them for inflation.

1
eCFR. 29 CFR 1630.2 – Definitions
2
eCFR. 29 CFR Part 1630 – Regulations to Implement the Equal Employment Provisions of the Americans with Disabilities Act – Section 1630.2
3
Office of the Law Revision Counsel. 42 USC 12102 – Definition of Disability
4
U.S. Equal Employment Opportunity Commission. Questions and Answers for Small Businesses: The Final Rule Implementing the ADA Amendments Act of 2008
5
Office of the Law Revision Counsel. 42 USC 12112 – Discrimination
6
U.S. Equal Employment Opportunity Commission. Enforcement Guidance on Reasonable Accommodation and Undue Hardship Under the ADA
7
U.S. Equal Employment Opportunity Commission. Time Limits For Filing A Charge
8
Office of the Law Revision Counsel. 42 USC 1981a – Damages in Cases of Intentional Discrimination in Employment
9
U.S. Equal Employment Opportunity Commission. Remedies For Employment Discrimination