For most people, a minor wound -- a blister from a new pair of shoes, for instance -- is nothing to worry about. It hurts and then goes away. But for some, sores or cuts just won't heal -- for months or even years. High blood sugar, circulation problems, smoking, peripheral neuropathy, aging, and malnutrition can all cause long-lasting wounds that don't heal.

"Chronic wounds are an awful and underappreciated problem," says Gerald Lazarus MD, director of the Johns Hopkins Wound Center and chief of dermatology at the Johns Hopkins Bayview Medical Center in Baltimore. "They're painful, ugly, and debilitating."

They can be socially isolating too. People are often ashamed of how the wounds look and -- in some cases -- how they smell, Lazarus says. Chronic wounds are also a sign of a potentially serious underlying condition that needs treatment.

Up to 2% of people in the U.S. have chronic wounds. If you have a wound that just won't heal, it's not enough to bandage it every day and hope it goes away. You need help. Here's what you should know about healing a chronic wound.

What Causes Chronic Wounds?

Doctors consider any sore that doesn't heal within six weeks to be a chronic wound. Although the wound clearly needs medical care itself, it's really a symptom of deeper health issue, Lazarus says.

"Healthy people don't get chronic wounds," Lazarus says. "You need to discover and treat the underlying problem that's causing them."

Some of the most common include:

• Chronic venous insufficiency, diabetes, and other circulation problems. For a wound to heal well, it needs good blood flow. Chronic venous insufficiency -- a circulation problem in which blood tends to accumulate in the veins of the legs -- causes about 60% of all chronic wounds. Diabetes also causes poor circulation, and it's another leading cause of chronic wounds, Lazarus says. People with diabetes may have nerve damage in their feet that prevents them from feeling an injury. Plaque in the arteries -- atherosclerosis -- can also cut off blood supply, causing wounds that don't heal.
• Pressure. In people who are in a bed or wheelchair, pressure ulcers, or bedsores, are a common problem. Since the pressure never lets up, the wound never gets a chance to heal. "I've met people who are paraplegic who tell me that they've almost come to grips with their condition," says Lazarus. "[But] what they're really worn out by is dealing with this awful, messy wound that won't heal."
• Surgery or radiation treatment. Surgery or radiation treatment for cancer can sometimes cause lasting damage to the skin that won't heal.
• Other health problems. Many conditions -- ranging from bowel disease to rheumatologic problems such as lupus -- can contribute to chronic wounds.

Other factors can play a role in chronic wounds. The overuse of antibiotics, allergic reactions to wound dressings, and common drugs such as corticosteroids and NSAID pain relievers can affect wound healing.

Lazarus says that chronic wounds are a serious and growing concern in the U.S. Why? "I think the rise in obesity is the biggest problem," he tells WebMD. Obesity is related to the growth in diabetes. It also makes conditions such as chronic venous insufficiency worse.

Chronic Wound Treatment

Untreated, the consequences of chronic wounds can be serious. In the U.S., chronic wounds related to diabetes and skin ulcerations are the most common reason for foot and leg amputations. However, experts have a number of good treatments for chronic wounds.

• Wound cleaning. Cleaning the wound with a sterile saline solution or wound cleanser will help prevent infection and keep the area moist.
• Surgery. Debridement is one type of surgical treatment in which a surgeon removes dead or infected tissue so a wound can heal normally.
• Antibiotics. Antibiotics -- either oral or intravenous -- are often crucial in fighting off infection in a chronic wound.
• Oxygen treatment. In this approach, the person rests inside a hyperbaric chamber filled with 100% oxygen. The treatment increases the oxygen levels in your blood, which may help speed up healing.
• Wound dressings. Different types of wound dressings can help with healing and protect the wound from infection and injury.
• Cell therapy and growth factors. Doctors heal some chronic wounds with skin grafts or new treatments that encourage cell growth. Some special wound dressings are made from living tissue. When applied to the skin, they may heal chronic ulcers on the legs and feet.
• Compression dressings. In people with circulation problems, tight compression dressings can help prevent the blood from accumulating in the legs. More common compression stockings, which are available in the drugstore, may help as well.
• Negative pressure wound healing. This technique uses a device that creates suction on the wound. It removes debris and pulls the edges of a wound closer together, making it more likely to heal.
• Offloading. This simply means removing pressure from a wound. Special shoes or other devices can reduce pressure on foot and leg sores, allowing them to heal.
• Good control of the underlying condition. Part of wound care is treating the underlying problem. Take medications if you need them. Follow your doctor's recommendations about lifestyle changes, such as losing weight, eating a healthier diet, and exercising more.

Getting treatment quickly is crucial. "A lot of patients could be helped if they came to the physician earlier," says Lazarus. "Once a wound becomes chronic, it becomes much more difficult to heal."

Getting Help for Chronic Wounds

If you have a chronic wound, you need expert care. Ask your doctor if there's a wound care center in your area. People with chronic wounds often need the collaboration of different experts, such as dermatologists, cardiologists, surgeons, diabetes experts, and others.

Healing a chronic wound may take a few different approaches. "If the wound isn't getting better or smaller after four weeks of treatment, you need to try something else," says Lazarus.

If you have a sore that just won't heal, don't wait to check in with your family doctor at your next physical. You need active, consistent medical care. The sooner you get help, the better your prognosis.