Sometimes it is obvious to others when a person has a disability. If you carried a white cane, wore hearing aids or used a wheelchair to get around, people around you could tell that you might have a disability with a mere glance. However, not all disabilities are readily apparent to outside observers. In fact, according to the University of Massachusetts, 96% are invisible disabilities, meaning that there is no outward sign of them.

The Americans with Disabilities Act does not provide a list of conditions that qualify as disabilities. Rather, it defines a disabled person as someone with one or more major life activities substantially limited due to a medical impairment, whether physical or mental.

Some invisible disabilities arise from chronic medical conditions, such as sleep disorders, renal failure or diabetes. However, the presence of a chronic medical condition does not necessarily mean that you have a disability. If you are able to perform all major life activities without limitation, you do not fit the ADA’s definition of a disabled person.

Most invisible disabilities are neurological in nature. Fibromyalgia, which causes chronic musculoskeletal pain, is a good example. Learning disabilities and attention deficit hyperactivity disorder are other examples. Other invisible may involve additional systems. For example, lupus and inflammatory bowel disease are immune disorders, while asthma is a respiratory disease and endometriosis affects the female respiratory tract.

If you have an invisible disability, you may meet with skepticism or hostility from others. They may assume that you are imagining your symptoms or pretending to have a disability to gain sympathy. Nevertheless, if you meet the ADA’s definition of a disabled person because of your condition, you have the right to request reasonable accommodations from your employer.