Have you ever wanted to talk to someone, but felt like you were intruding so you never did? Have you ever needed a favor from someone, but been too scared to be a bother? If you have then maybe you're experiencing normal anxiety, but for many these are only but two scenarios that occur in their fight with anxiety.
Picture this, you're in a restaurant. You're a Vegetarian and ask for a salad without meat. The waiter acts as if they have heard you, and you feel proud of yourself for going the extra step of asking( A lot of times someone with anxiety will not even ask for anything removed, instead they'll just pick what they don't want off themselves). Then the waiter comes back and gives you a salad that has meat on it. You don't tell anyone around you, instead, you sit there and pick the meat off the salad. It wasn't your fault and the waiter would surely have the problem fixed for you….but in your head all you hear is, "Don't be a bother."
Picture this, you're in a group project. You have some good ideas and you want to share them with the group. After sitting on what you want to say for a good amount of time, you decide what you thought wasn't good at all. You allow your group to settle on a different idea and hope they distribute the work load evenly. Wait, someone in the group has asked what everyone wants to do. Everyone chooses the easiest part for themselves, and you get stuck with a work load that you know you will have a hard time with… But you act as if you are okay with what has been given to you, and you attempt to do your part sufficiently. When your group meets again you will have all of your work done, and the rest of your group will have barely started.
Picture this, you have a giant crush on this person. They obviously feel similar to you and are dropping subtle hints. They flirt and you do so in your own way. It comes down to them asking you if you want to go on a date. You say yes and get excited for the day to come. As the day gets closer you get more excited, you have exactly what you want to wear down. When the day finally comes, though, you feel nervous and decide you don't want to do this anymore. All of the things that make you inadequate run through your mind and you decide you're not good enough for this date. You end up canceling. You tell the person you had a family emergency and lay in bed the rest of the day picturing what the day could have been like.
These are common situations people with anxiety go through. It influences their happiness, but they do what they believe is managing. Every human being will have some anxiety, but the difference with a bit of anxiety and having anxiety is the proportion and scale of these occurrences. Someone with true anxiety makes every situation a hassle and most of the time don't go through with what they want. If you are out and about look for the signs that someone is feeling anxiety. Look at their body language, how they make eye contact, the pause when they are asked a question.
Be understanding, be kind, and be helpful.