A chronic wound is practically defined as one that does not heal within 3 months.
However, if you are diabetic, elderly, have sickle cell disease, or confined to a bed or chair-- seek medical attention immediately upon any break your skin, as these are common risk factors for developing chronic wounds and early action can significantly increase the rate of healing.
Normally, wounds progress through four phases of healing:
Inflammatory Phase
Proliferative Phase
Remodeling Phase
Epithelialization Phase
Chronic wounds, however, become caught in one or more of these stages.