Collocations for alarmed - adj.

be, feel, look, seem, sound
become, get, grow
She began to grow alarmed when she realized how late it was.

extremely, fairly, very, etc.
seriously
increasingly
a little, slightly, etc.
(not) unduly
The government is not unduly alarmed by these figures.

at
She was alarmed at the prospect of being alone.

by
I was slightly alarmed by what Susan told me.

nothing to be alarmed about
The doctors have decided to keep him overnight but there is nothing to be alarmed about.