A chronic wound is a wound that takes a particularly long time (three months or more) to heal and doesn’t follow the normal reparative sequence. Potential reasons for a chronic wound include disorders that affect blood and oxygen circulation such as neuropathy and diabetes; a suppressed immune system tied to medications or systemic disease; the effects of old age on the skin; continued re-injury of the site; emotional stress; or possibly a malignancy. People who smoke or have blood, heart, lung or kidney disease are at greater risk for a chronic wound. Some examples of chronic wounds include diabetic ulcers, vascular ulcers and pressure ulcers. Chronic wounds may require treatment from a specialist in wound care, who in addition to cleaning, debriding and properly dressing them may also apply negative pressure wound therapy or possibly hyperbaric oxygen therapy to help speed up the healing process.