How would I know if I have stress?

Some things might make us stressed e.g., an exam coming up, going on a first date, a family drama etc., but once these situations pass or they get sorted, you feel better.
Experiencing stress is temporary. This is the difference between anxiety and stress – stress doesn’t hang around like anxiety does. Stress and anxiety might share similar symptoms – just the intensity and duration are different. Take for example, if a spider drops down in front of you (and this is worse if you really dislike spiders!) you might yell, scream, swear, and you would probably jump back or wave your arms around. If the spider scrambles away, the stress you are feeling gradually reduces and you can go back to what you were doing after a while.
You can do it picture by Kayden Baldock

When you first saw the spider, your heart started to beat faster than you could say OMG – it’s an automatic response and one that you can’t control. You might also feel a bit shaky or sweaty. It just happens. This is because our brains are wired for threat. It’s a survival mechanism that lives in an older part of our brain. Take a look at this video about the three emotion regulation systems in our brain – pretty interesting stuff which helps to understand why we can feel the way we do when under pressure.

Have you had to stand up in front of your class and present a topic? As your turn is coming up, you might start to notice your heart rate getting faster, you might feel flushed in the face, or start to sweat, you might feel shaky, or feel ‘butterflies’ in your stomach. This is stress! But then, when it is your turn, and you start to talk, after five minutes or so, you feel a little less stressed, and by the time you finish, you feel better than when you started. Then when you finish and start to relax, you feel OK.