You are under the effects of a potent poison which causes you ongoing harm. Each poison will have its own individual effects, with some being more severe than others.
Recovery
Assuming they aren’t fatal, most poisons fade on their own with time. You can recover from them earlier with a successful System Check (UC Fortitude, DT is set by the poison). You can make one Check per day of rest.
Recovering from a poison removes the poison and any inflicted Status but does not heal any Vitality lost to it or other Afflictions it causes.