Her overreaction to the situation made things worse.

There were many overreactions to the news.

She tends to overreact to small problems.

She always overreacts to small problems.

She is overreacting to the situation.

She overreacted to the situation.

She is known for being overreactive to small problems.

Her overreactivity to criticism often leads to unnecessary arguments.

The overreactivities of the students were causing unnecessary stress.