A troubled or anxious state of mind
Breathing in and out slowly for several moments will reduce his feelings of anxiousness.
Uncontrollable anxiousness that interferes with daily life is clinical anxiety, or generalized anxiety disorder (GAD).
Most common side effects reported are behavior changes and frenzied activity or anxiousness.
It's even about the people you aren't fond of, which means awkwardness and anxiousness.
In general, anxiety is a normal reaction to acute stress, and a little anxiousness can be good for you.