Last weekend, I went to a speed-dating event. Just walking up to the door made the hairs on the back of my neck stand up.

I like to think of myself as a social, outgoing person. But when it comes to anything related to dating, I can be painfully shy.

A speed dating event in the U.K. Photo by Jack Taylor/AFP/Getty Images.

As I got closer to the building, I started to feel like there was some horrible, inaudible, invisible static in the air that only I could sense. To anyone else, I'm sure everything looked perfectly normal — the bar was nice, all the people I met were very lovely ... but I couldn't help but feel that static playing across the back of my neck.

I was, in other words, anxious.

Everyone gets anxious sometimes, and that's OK.

Image via iStock.

In fact, anxiety is a normal and evolutionary biological response to stressful situations. Our brains are really good at linking bad experiences (like awkward dates) and stimuli together, mostly because it keeps us safe.

If something bad happens and then you're in a similar situation in the future (like, say, having to talk to nearly 20 strangers in five-minute increments), your brain holds up big signs to help you remember to stay safe — signs like that prickling feeling on the back of my neck.

Other signs can be mental symptoms, like hypervigilance or intrusive thoughts, or physical ones, like a racing heartbeat or feeling nauseous or dizzy. And these can sometimes be really, really hard to ignore.

"[Anxiety is] a whole-body, a whole-mind, a whole-person experience," Dr. Michael Irvine told Upworthy.

Irvine is a clinical psychologist who knows a lot about anxiety. He's worked extensively with combat veterans experiencing post-traumatic stress disorder, a diagnosis that, at its heart, is about anxiety.

“It’s not just battling your thoughts. The work isn’t just trying to convince yourself not to be scared. Anxiety is a reflex."

Irvine explained that fighting off anxiety isn't as simple as just ignoring those anxious feelings.

“It’s not just battling your thoughts," said Irvine. "The work isn’t just trying to convince yourself not to be scared. Anxiety is a reflex."

And anxiety doesn't just affect our bodies and minds; it can actually affect how we see the world every day.

An anxious job applicant, circa 1940. Photo by Rondal Patridge/National Archives/Wikimedia Commons.

An experiment from the Weizmann Institute of Science in Israel showed clearly that having anxiety can affect our ability to process sights and sounds.

Researchers from the lab set up the experiment by training volunteers with specific sounds. They taught them that some sounds had good outcomes (gaining money), and some had bad outcomes (losing money).

Then they played the good and bad sounds, plus some benign and neutral ones, back to the volunteers. And what they found was fascinating: The volunteers with anxiety were more likely to identify benign sounds as bad sounds, too, even though those sounds were neutral.

Why? It wasn't a conscious decision. Instead, the anxious volunteers' brains had automatically overcompensated. In trying to keep them safe, their brains had changed the way they perceived all the sounds, not just the bad ones.

This might sound like an odd scenario, but it helps to explain why the speed-dating event was so weird for me. To outsiders, the event looked like a couple dozen young people enjoying themselves. But to my brain, through the filter of anxiety, the event was suddenly attached to bad dates of years past and uncomfortable social interactions. What might seem benign to everyone else actually looked much worse to me.

Sometimes, though, our brains take it too far.

Anxiety is normal — especially after a bad event — but, similar to how an overactive immune system can give us allergies, our brain's natural protective response can sometimes overcompensate. And when anxiety progresses to the point where it disrupts your everyday life, that's when it becomes what psychologists would call an anxiety disorder.

The U.S. Army now requires soldiers take suicide awareness classes. PTSD, an anxiety disorder, may be associated with higher suicide rates in soldiers. Photo from Chris Hondros/Getty Images.

About 1 out of every 5 adults in the U.S. is affected by an anxiety disorder. Anxiety disorders come in a lot of different forms, too, ranging from social anxiety disorder to PTSD.

I don’t have a diagnosed anxiety disorder, but for folks who do, the symptoms can be really paralyzing. Those intrusive thoughts and physical symptoms can keep people with anxiety disorders from leaving the house. The symptoms can make them struggle at work and seriously affect their quality of life.

The stigma of having an anxiety disorder can be just as tough as the symptoms, too.

Image from iStock.

Even though 1 in 5 people struggles with it, people who are living with anxiety disorders often feel like they should be able to fix themselves alone — to pull themselves up by their bootstraps. In a 2007 survey, only 25% of people with mental health symptoms said they believed people would be sympathetic to their stories.

But in reality, anxiety is nothing to be ashamed of; it's just your brain working extra hard. Plus, talking about your struggles and looking for treatment early are some of the best strategies for managing it.

"The earlier we intervene on the timeline, the more likely an individual is to get a better outcome," said Irvine.

So biologically, it's not too weird to have a prickly-neck feeling or an upset stomach while meeting a bunch of strangers.

But when your brain is dealing with anxiety, especially an anxiety disorder, it actually functions differently. Things that might be benign suddenly seem scary. Meeting potential dates might make you really sweat. An overwhelming feeling of being unsettled might come over you just as you enter a new place that reminds you of an old place.

That is OK. Because even though we can't always control how our brains see the world, or what warnings signs they throw in our faces (needed or not), we've got nothing to be ashamed of when we start to feel anxious.

And if you ever run into me at another speed-dating event, I hope you'll cut me some extra slack.