All effects currently active on a combatant are displayed on the Active Effects pane. This will provide a quick view of the effect description, duration, and source. This pane also allows you to sustain effect and cancel effects.

As shown below:

The colors have a special meaning:

Blue

The effect is beneficial to the target, this is relevant only when the source delays a round and the effect end at the end of it's turn

Orange

The duration box column may have an orange color, this indicates that the duration has something special. Either it's sustainable, or it's a effect were failing a save will cause additional effects (like in the Sleep power)

At the bottom of this pane are two buttons:

Sustain

Clicking this button will sustain an effect, however this will only cause effect if the effect is bound to end at the End of the current Turn (duration is EoT)

Cancel Effect

Will remove the effect from the list.

As will all tracked object, you can undo actions in case an invalid command was executed.

Editing

All effect descriptions (except Mark effects) can be edited by double clicking on the description on the table in the Active Effects pane. Place the new text and press Enter. This is not supported for mark, in this case simply add a new mark.