What is 'anxiety'?

English is my second language and I don't live in an english speaking country, so my exposure to native speakers is rather low. I often see the term 'sth. triggers my anxiety' (e.g. this workplace question in which OP says 'constantly triggers my anxiety' about a co-worker).

According to wikipedia, 'anxiety' is a medical condition, but in most use cases, it sounds like it's rather used to describe generally awkward or uncomfortable situations.

Similarly in this blog ('19 Everyday Things That Could Trigger Anxiety'), in which 'You’re thirsty' is mentioned as one reason of experiencing anxiety.

So is 'anxiety' (currently?) an umbrella term for many different negative feeling?

The word anxiety is similar to depression in that its meaning in general speech is much broader than its meaning as a medical term.

In general, every day speech anxiety means

A feeling of worry, nervousness, or unease about something with an uncertain outcome.

So, for example, you can say that waiting for your exam results is causing you some anxiety without it meaning that you're suffering from a medical complaint.

There is another non-medical meaning, where it represents a

Strong desire or concern to do something or for something to happen

For example, you could say that you were anxious for those exam results to arrive which would mean that you were eager for them to arrive rather than you were worried about them arriving.