Pressure injuries are typically caused by extended pressure on the skin and underlying tissue. You may also hear them referred to as pressure sores or bedsores. Although they usually affect those who are confined to bed or who sit in a chair or wheelchair for long periods of time, they can happen to anyone. 

Venous stasis ulcers usually develop on the inside of the leg, just above the ankle. They can occur when there's been high pressure in the veins of the leg, usually as the result of a minor injury. 

Arterial ulcers can develop when there is a lack of blood flow to skin on the ankle, feet, heels or toes. You may also hear them referred to as ischemic ulcers or ischemic wounds. They're commonly caused by peripheral artery disease, which is reduced blood flow due to narrowing of the arteries.

Wounds caused by autoimmune diseases can be difficult to identify. Although they're similar to wounds in other conditions, a tissue biopsy may be needed to identify the correct course of treatment. These wounds require a multidisciplinary approach to treatment, and can occur as a result of the following diseases:
 

• Arthritis
• Calciphylaxis
• Lupus
• Pemphigoid
• Psoriasis or psoriatic arthritis
• Pyoderma gangrenosum
• Scleroderma

Malignant wounds typically contain easily irritated or necrotic (dead) tissue. They require a multidisciplinary approach and may be difficult to heal without systemic treatment or treatment of the cause (e.g. cancer).

Traumatic wounds are most commonly caused by an injury resulting in a cut, laceration or puncture, such as stepping on a nail or cutting your finger with a knife. 

After a surgical procedure, you may have a wound that isn't healing normally. These are non-healing surgical wounds, and a common cause is infection at the surgical site. Medical conditions that cause decreased immune function, such as diabetes, can contribute to surgical wounds that won't heal.

Soft tissue radionecrosis is the death of soft tissues occuring as a result of radiation exposure. Soft tissue radionecrosis can cause extensive tissue death, leading to open sores on the skin. This type of wound can occur months, or even years, after ionizing radiation treatment.