Anxiety is your brain’s emotional alarm system. With alarm systems, it may be going off because there’s a burglar, it may just be a cat. So anxiety can rise because of a reason that requires action or it could be a false alarm.
There are things that make it more sensitive. Lack of sleep, caffeine, drinking alcohol regularly, background stress levels can all contribute.
exercise is a good suggestion to reduce it in general. Lifting weights particularly helpful for me. Meditation also good. Cut caffeine and alcohol completely if possible.
in the moment, I mainly use mental maths as a distraction (100-7 for example and then keep going down, or count the number of blue cars, or whatever). Or the 5–4-3-2-1 method: name 5 things you can see, 4 things you can hear, 3 things you can feel, 2 things you can smell, and 1 thing you can taste (carrying sour sweets or strong mints and some lavender hand cream helps with this one). Key thing with the coping strategies is to try them out when the anxiety isn’t too bad and decide which ones you like. And remember none will work all the time - so it’s good to have a repertoire.
And when my anxiety is up, I sometimes have to stop listening to the news for a bit and step away from social media. Seems to make it worse.