“But you don’t look disabled.”

Imagine asking for an accommodation that you need and being denied because the person who could give it to you believes that you’re lying. Imagine using an accommodation that you need and being subjected to dirty looks or rude comments from strangers who, with no knowledge of your needs, symptoms, or medical history, have concluded that you’re lazy, a faker, or a scam artist. This is the reality for millions of people who suffer from what are often called invisible disabilities.

Invisible disabilities are real, diagnosable medical problems that aren’t necessarily visible to strangers.

It’s easy to think of a person with disabilities as a person in a wheelchair, or a person wearing sunglasses and carrying a white cane. But disabilities come in many forms. A person with chronic pain, mental illness, epilepsy, or multiple sclerosis may appear perfectly healthy to a stranger, but that doesn’t mean that they are healthy or that they feel fine. Take a look at a few things that everyone should know about invisible disabilities.

1. More People Have Invisible Disabilities Than You Think

There are a lot of reasons why you may not realize how common invisible disabilities are. It isn’t just because people who have invisible disabilities don’t look the way you think disabled people look. It’s also because invisible disabilities are often not talked about.

Some invisible disabilities carry stigmas. For example, people who admit to having mental illnesses are sometimes viewed as unstable or even dangerous, even when their illness is well-managed. People who suffer from mental illnesses are actually more likely to be victimized by others than to pose a danger to others. However, if you pay attention to how often the conversation around certain crimes – especially violent crimes – turns to talk of treatment for mentally ill people as a method of preventing future crimes, you may begin to understand why many people who suffer from mental illness would rather not mention it. They know they may face discrimination from people who don’t understand and who make assumptions about what it means to have their condition.

Another reason why people with invisible disabilities may not talk about them is that they’ve experienced being accused of lying, overreacting, and plain old laziness – sometimes even by medical doctors. Illnesses like chronic fatigue syndrome and fibromyalgia, for example, are difficult to diagnose. People who suffer from these types of disabilities often experience being misdiagnosed and having their symptoms dismissed more than once before finally finding a doctor who takes them seriously. When it’s so difficult to explain their illness and get appropriate treatment from people with medical degrees, it’s no surprise when they aren’t interested in explaining it to strangers.

Other people may simply want to keep their medical information private. You probably wouldn’t want to answer anyone’s questions about your medical history while you’re trying to use a public restroom or park in the grocery store parking lot. People with invisible illnesses aren’t interested in doing that either. They want to be able to go about their lives without having to constantly explain themselves, just like you would.

2. Symptoms Aren’t the Same All of the Time

A person who suffers from a chronic pain disease may need to use accessible parking spaces during a flare-up when their symptoms are especially severe. They may not be able to easily walk all the way from the regular parking spaces to the entrance of the building on those days. However, at other times, they may be able to park and walk from a further distance. Does that mean that they’re faking it on the days when they need accessible parking? No.

Many conditions have symptoms that vary in severity from time to time. A person who has arthritis may suffer more when the weather is cold or wet. A person suffering from multiple sclerosis may feel perfectly fine for weeks, months, or years, then experience a symptom like vision loss or impaired coordination without warning. You should never assume that because someone doesn’t always need an accommodation, they never need an accommodation.

In fact, this same type of incorrect assumption also affects people who live with visible disabilities. For example, many people who need to use wheelchairs are able to stand and even walk short distances, at least some of the time, but this is sometimes seen as evidence that the person is faking their disability. It’s always best to assume that the person with the accommodation does have a disability and knows what they need.

3. It’s Never Your Job to Disclose Someone Else’s Disability

Invisible disabilities are often misunderstood, but once people do understand, they often want to help. If someone tells you that they have a disability that you didn’t know about, you may be on the lookout for opportunities to help out. That’s commendable, but often well-meaning friends and loved ones can take things too far.

It’s not your job to inform bosses or co-workers about another co-worker’s disability, even if your intention is to make sure that accommodations are made for them. If you’re accompanying a friend who has a disability to the store, it’s not your job to explain to rude passers-by why your friend needs to park in the accessible parking spot.

People who suffer from these disabilities know that they may face judgment, harassment, invasive questions, or even discrimination, and sometimes it’s easier for them not to disclose their condition to others. Keep in mind that the person who has the disability has been navigating their life with the disability for some time, and they know what works best for them. Even if you disagree with them, it’s their information to disclose and it’s not up to you to override their wishes. It’s wonderful to be supportive of a friend or loved one who has a disability, but let the person who has the disability take the lead. If you want to be helpful, ask them what kind of support they need, and then do what they ask.

Living with a disability is hard enough, and being constantly questioned or doubted about your disability just adds another layer of difficulty. Keep in mind that just because you may not be able to see another person’s struggles, that doesn’t mean they aren’t real.