Americans with Disabilities Act Disability (as amended by ADAAA) means-

A Physical or Mental Impairment that Substantially Limits one or more of the
Major Life Activities (MLA) or being
Regarded As having such an impairment or
A Record Of such an impairment

Definitions/explanations of the above terms:

Physical or Mental Impairment means a physiological or mental disorder, cosmetic disfigurement, or anatomical loss affecting a body system or mental disorder or disability, emotional/mental illness, & specific learning disabilities.

Substantially Limits to be construed broadly in favor of coverage and is measured against ability of an individual to perform as compared to most people in the general population.

Major Life Activities are activities such as caring for oneself, manual tasks, numerous bodily operations, and working. Also, operation of a major bodily function or an individual organ. “Major” shall not be interpreted strictly.

Determination of whether impairment substantially limits a MLA shall be made without regard to effects of mitigating measures. An impairment that is episodic or in remission is a disability if it qualifies when active.

The following impairments will almost always result in coverage: deafness substantially limits hearing; blindness limits seeing; intellectual disability limits brain function; autism limits brain function; cancer limits normal cell growth; diabetes limits endocrine function; multiple sclerosis limits neurological function; depression, PTSD, obsessive compulsive disorder limits brain function.

Considering the manner, condition, or duration of performing the MLA, as opposed to general population, should be done to determine a disability. The focus is on how a MLA is substantially limited and not on what outcomes a person can achieve. For example, someone with a learning disability may achieve a high level of academic success, but may be substantially limited because of the additional time and effort involved compared to general population.

Regarded As (RA)- A person is RA if the person is subjected to a prohibited action because of an actual or perceived physical or mental impairment, whether or not that impairment substantially limits, or is perceived to substantially limit a MLA. A person is RA any time an employer takes a prohibited action against the person because of an actual or perceived impairment, even if the employer asserts, or may or does establish a defense to such action.

Record Of (RO)- A person needs a written record of an impairment to qualify.