I just read that anxiety is a reaction to feeling like things in life are out of one's control. Though people often feel that is true of tests ('Who knows what they will ask me?' etc.), it is less true in tests than some might assume, because people have control over how much they study and prepare. Your son should also know that (unless a particular instructor is a sadist) a test is simply designed to show what someone knows, or knows how to do. I hope your son will realize it's a neutral situation, not a negative one designed to trap him, and will also see that everyone will love him who loves him now no matter how he does on his tests.
You might find better help on the anxiety forum -- this is the weight loss forum. There's a difference between anxiety and nervousness. Some people get nervous and some don't on tests. Everyone has something they get nervous about. Anxiety is a different thing, and when it's irrational or chronic it's an emotional problem. If it's just tests, well, lots of people have this problem. Know that it's not the test itself that's the problem, it's the way your son is thinking about the test. If he gets nervous about lots of things, again, that's an emotional problem. If it's just tests, then he just needs to work on that. The more you do something, the easier it should get, as the brain learns there's nothing to fear. Also, calmness is sometimes overrated when it comes to performance -- a lot of very successful people, including most pro athletes and celebrities, get nervous before performing, but the adrenaline this creates actually can help push us to perform. For others, it can be a handicap. In my family, I loved tests, it was like a game and it was finally my turn to get to talk, so to speak. My brother got nervous about them. Same family. I would say a psychologist would help is this is a generalized problem, but if it's just tests, it might be better to find someone who works with folks on that specific problem. All the best.
Such a common problem! I have one son with intense anxiety (about most things) but in particular school work and one who probably could use little more. The plus side of anxiety is that it keeps you on your toes and motivated to do well and the down side is that it can derail you during the test. My son with anxiety has found a few things help. One is that he takes deep breaths. If he pictures blowing out candles on a cake, for example, it helps him get the deep calming breaths he needs. He also is in high school and is allowed to have chewy mints in class. These help I two ways. First, many people are soothed with oral activity (chewing gum, chewing on things in general and even smoking qualifies) and mint is alerting.
Is your child a perfectionist by chance? My son is and failure just isn't an option in his mind. Failure means getting one point off too! He's extremely hard on himself. We do a lot of talking about no one expecting him to be perfect but him! And that as long as he does his best, the outcome is okay. I expect him to study and try his best but past that, there is so much you can control. Proper preparation helps with anxiety. Unless your son is like mine and has anxiety in general.
But some kids just freeze. I describe it like this . . . your brain is a high way. Information is speeding along. But if stress and anxiety comes on, it's like a pile up and the information stops moving along the high way or slows way down. And it gets worse and worse as the cars begin to pile up. So, keeping the high way free of the stress is really key.
What grade is your son in? Things like ACT prep books have really helpful tips for test taking in general. And we found the same kind of info in a Core subject 8th grade practice book. There are strategies when taking tests that help if you get lost. An example for a reading test . . . don't read the passage first, read the question first and look for the answers to the question only rather than the other way around.
Tell us more about your kiddo and we'll try to help!