What triggers random anxiety and panic attacks when nothing is going on?

Chemicals in the brain causing a you to go into fight or flight mode. And remember the smallest thing you might not even notice is the underlying reason for the attack. Therapy can sometimes help find these triggers

There doesn't have to be a reason to experience anxiety and panic attacks. Unfortunately, sometimes they just happen. Since you can't always avoid them, it's good to be prepared with some coping techniques like mindful breathing.

When nothing is going on, your mind is empty and thoughts that are unwanted may arise. This mainly causes/triggers random anxiety and panic attacks. Because you start thinking about things you shouldn't or don't want to or can't. It's a human tendency sort of thing.

Panic attacks usually have an underlying cause. It might be subconscious depression, self-esteem issue etc. They may manifest like this. It's wise to treat anything that brings you worry or sadness in life.

Anxiety is a basic reaction evolutionary wise to responding to attacks. In our society it's not always needed, other times it is useful. But the main point is, sometimes you get anxiety when you feel like it's neccessary but infact nothing is going on, this triggers because some people are more prone to anxiety over to other people. Normally these people that are prone to it over others, have experienced something tremendous in the past or even have unnecessary fears in daily life, that can be helped with either psychotherapy or medication to decrease anxiety levels.

Everything can trigger it. Whether it's a certain person who said something that made you feel uncomfortable or reminded you of an unfavourable past experience, or simply the stress of work/school load.

Sometimes we need distractions to keep our minds from going to negative places, which leads to anxiety and panic attacks, so it's totally understandable if someone feels extra anxious for seemingly no reason while there are no distractions, even if there is not a specific problem. Some people are so used to anxiety that a lack of problems to be anxious about can cause them to feel anxious because they are in unfamiliar territory. The next time nothing is going on, try to anticipate future restlessness by planning events or activities for yourself!

A lot of the time it's subconscious and you only realize until the panic attacks occur and you become overwhelmed. Anxiety can be unexplained until you look back and think about your day and what's happened.

talking about a sad past or ther mention of certain names in a certain way it hurts to remember and flares me up

Just the thought that something could go on later, the fear of something go on later, the fear causes anxiety, and also the fear of having fear.