A skin ulcer is an open sore caused by poor blood flow.

Good blood flow is necessary for wound healing. But if you have blood circulation problems, minor injuries can’t heal properly. Over time, an injury can turn into a skin ulcer.

If an ulcer becomes infected, it should be treated quickly. Infected sores are serious because the infection can spread throughout the body.

Often, skin ulcers affect the legs. Up to 3 in 1,000 people have active leg ulcers. They can also show up on the feet, back, and hips. Skin ulcers are more common in older people.

Your symptoms, treatment, and recovery will depend on the specific cause of your ulcer.

Generally, a skin ulcer looks like a round open sore in the skin. The outer border might be raised and thick.

In the early stages, you’ll notice skin discoloration in the area. It might look red and feel warm. If you have a darker skin tone, it may look shiny or blue.

As the skin ulcer gets worse, it will look like a crater. It might weep clear fluid or blood.

Other symptoms depend on the type and severity of the ulcer. You may notice:

  • swelling
  • redness
  • tenderness
  • itchiness
  • pain
  • skin discoloration
  • changes in skin texture
  • yellow or green pus (due to an infection)

Skin ulcers happen when there’s a problem with blood circulation. Causes of poor blood flow include:

Diabetes

Diabetes is a disease that causes high blood sugar. Over time, high blood sugar can lead to nerve damage called peripheral neuropathy. You may lose sense of touch in your feet and legs.

Since you can’t feel pain or pressure, you won’t feel injuries on your legs or feet. High blood sugar also slows down wound healing.

If left untreated, injuries can turn into skin ulcers.

Atherosclerosis

Atherosclerosis, or arteriosclerosis, occurs when the arteries become narrow due to fat buildup called plaque.

Normally, the arteries deliver blood throughout the body. But when the arteries narrow, they can’t properly circulate blood.

If part of your body doesn’t get enough blood, the skin tissue breaks down and forms a sore.

You’re more likely to develop atherosclerosis if you have diabetes.

Pressure

If you stay in one position for too long, the constant pressure will squeeze your blood vessels.

This blocks blood flow to skin tissue. Eventually, the skin dies and develops an ulcer.

Venous insufficiency

Venous insufficiency occurs when your veins can’t send blood from your legs to your heart. Blood collects in your leg veins, which leads to swelling.

If the swelling is severe, it can put pressure on your skin and cause ulcers.

Causes of venous insufficiency include varicose veins and blood clots.

You’re more likely to get skin ulcers if you have certain risk factors. These include:

  • Pregnancy. During pregnancy, hormonal changes and increased blood volume may cause leg vein problems.
  • Cigarette smoking. Tobacco smoke hardens your arteries and disrupts proper blood flow.
  • Limited mobility. Being bedridden, paralyzed, or using a wheelchair puts your skin under constant pressure. Leg injuries and arthritis can limit your movement.
  • Increasing age. Age is linked to atherosclerosis and venous insufficiency.
  • High blood pressure. Hypertension, or high blood pressure, damages the arteries and disrupts blood flow.
  • High blood cholesterol. High cholesterol increases narrowing and oxidative stress in the arteries, which disrupts blood flow.
  • Obesity. Obesity raises your risk for diabetes, atherosclerosis, and increased pressure in your leg veins.
  • History of blood clots. If you’re prone to blood clots, you’re more likely to have blood flow issues.

If left untreated, a skin ulcer may become infected. This can prolong the healing process.

The infection can also spread to deeper tissue, bones, joints, and blood.

There are four types of skin ulcers. Each one has a different cause and slightly different symptoms. Skin ulcer types include:

Decubitus (pressure) ulcers

Decubitus ulcers are caused by continuous pressure or friction on the skin. They’re also called pressure ulcers and pressure sores.

These ulcers often develop on bony areas, because the bones place extra pressure on the skin.

Decubitus ulcers usually affect the:

  • back
  • hips
  • buttocks
  • ankles
  • heels

Venous skin ulcers

Venous skin ulcers are caused by poor blood circulation in the leg veins. They usually affect the leg between the knee and ankle.

About 80 to 90 percent of all leg ulcers are venous leg ulcers.

Arterial skin ulcers

Arterial ulcers, or ischemic ulcers, happen when blocked arteries cause poor blood flow.

These ulcers commonly form on the:

  • lower leg
  • feet
  • heels
  • toes
  • outer side of ankles

Usually, arterial ulcers are very painful. Pain might get worse at night or when the legs aren’t moving.

Neuropathic skin ulcers

Neuropathic ulcers are caused by nerve damage and narrow arteries. They’re also called diabetic foot ulcers.

These ulcers typically occur on the pressure points of the foot. This includes:

  • heels
  • toes
  • bottom of feet

Because of nerve damage, you likely won’t feel pain. But you might notice clear fluid on your socks.

Neuropathic foot ulcers affect about 15 percent of people with diabetes.

A doctor can perform different tests to diagnose your sore. This might include:

  • Medical history. This information can help your doctor better understand your symptoms.
  • Physical exam. Your doctor will examine the size and depth of your sore, and look for blood, fluid, or pus.
  • Blood test. If your ulcer is infected, a blood panel will show how your body is fighting the infection. A blood test can also show underlying problems.
  • Tissue or fluid culture. This test can determine what kind of bacteria is causing your infection so your doctor can prescribe the right antibiotics.
  • Imaging tests. An X-ray, CT scan, or MRI helps your doctor look at the tissue and bone under the sore.

If you have a mild skin ulcer, home remedies may speed up the healing process.

For serious sores, check with a doctor before using home treatments.

Home remedies include:

  • Leg elevation. To help blood flow out of your leg, keep your leg above your heart. Prop it up on cushions or pillows.
  • Compression socks. Compression socks reduce leg swelling by helping blood flow back up to the heart.
  • Saline solution. If you have a mild skin ulcer, you can clean it with sterile salt water called saline. If your ulcer is severe, a wound-care nurse should do it instead.
  • Turmeric. Turmeric has antimicrobial, antioxidant, and anti-inflammatory properties that may help wound healing. To use it, mix a 2-to-1 ratio of ground turmeric and water and gently apply the paste on the sore.
  • Honey. Traditionally, honey is used for wound healing because it has anti-inflammatory and antimicrobial benefits. To try this method, apply high-quality honey to a dressing, then apply the dressing on the skin.

The goal of skin ulcer treatment is to heal the wound, reduce pain, and treat any infection. Your treatment may include:

Dressing

Dressings protect the wound and keep it clean. This promotes healing and prevents infection.

The type of dressing depends on your ulcer and your doctor’s preference. Examples include moist dressings, hydrogels, hydrocolloids, collagen wound dressings, and antimicrobial dressings.

Always follow your doctor’s instructions. They’ll explain how to clean the ulcer and change the dressing.

Antibiotics

If your ulcer is infected, you’ll need antibiotic ointment. If the infection has reached deeper tissue or bone, you’ll receive oral antibiotics.

Your doctor may prescribe antibiotics even if your ulcer isn’t infected. The antibiotics will reduce the risk of infection.

Pain medication

At first, changing the dressing will be painful. A doctor can prescribe medication to control the pain. The ulcer will be less painful as it gets better.

If you can’t feel pain or pressure, you likely won’t need pain medication.

Surgery

Typically, noninfected skin ulcers don’t need surgery.

If other treatments don’t work, or if you have a large sore, you might need a skin graft. This will close the wound and help proper healing.

Surgery may also be done to remove pressure by shaving away bone.

If a wound doesn’t heal within two to three weeks, get medical help. You might have a skin ulcer.

Early treatment will reduce the risk of infection and other problems.

Generally, skin ulcer recovery occurs within a few weeks to three months. Serious ulcers can take up to two years.

Complete recovery depends on:

  • type of ulcer
  • size of ulcer
  • quality of wound care
  • your overall health
  • blood circulation
  • pressure from walking or standing

Recovery may take longer if you have an infection, diabetes, or atherosclerosis.

Skin ulcers are open round sores. They develop when blood can’t flow to an injury. Causes of poor blood flow include diabetes, atherosclerosis, pressure, and vein problems.

Typically, skin ulcers affect the legs, but they can occur on the feet, hips, and back. Treatment depends on your ulcer and overall health. You may need to elevate your leg, wear compression socks or dressings, or take antibiotics or pain medication.

If you have a wound that won’t heal, or if you notice a skin ulcer, see a doctor immediately.