Skin ulcers are open wounds that develop when poor blood circulation prevents the skin from healing properly, turning even minor injuries into chronic sores that require careful medical attention and management to prevent serious complications.

Understanding Skin Ulcers and Their Impact on Health

A skin ulcer is an open sore that forms on the surface of the skin when blood flow becomes inadequate for proper wound healing. When blood circulation becomes compromised, even small injuries that would normally heal quickly can develop into persistent, painful wounds. These ulcers represent a significant health challenge because they can take months or even years to heal, and without proper treatment, they may become infected, leading to serious complications that can affect the entire body.^[1]

These wounds typically appear as round, crater-like openings in the skin. In their early stages, the affected area may show signs of skin discoloration, appearing red and warm to the touch, or shiny and blue in individuals with darker skin tones. As the condition worsens, the ulcer deepens and may begin to weep clear fluid or blood. The outer border of the ulcer often becomes raised and thick, while the center forms a depression that can extend through multiple layers of skin.^[1]

The severity of skin ulcers varies considerably. In the mildest cases, they remain superficial, affecting only the outer layers of skin. However, severe ulcers can become deep wounds that extend through muscle tissue, potentially exposing bones and joints. This progression through different stages makes early detection and treatment crucial for preventing long-term complications and disability.^[2]

How Common Are Skin Ulcers?

Skin ulcers represent a significant public health concern, particularly in developed countries. Among the most common types are leg ulcers, which affect approximately 1 to 3 out of every 1,000 people in Western countries. The prevalence of lower-extremity ulcers ranges from 1 to 2 percent of the general population, making them a relatively common medical condition that healthcare systems must address regularly.^[1][11]

The distribution of skin ulcers is not uniform across all age groups and populations. Older adults face a significantly higher risk of developing skin ulcers compared to younger individuals. This increased vulnerability stems from age-related changes in skin integrity, reduced tissue resilience, and a higher prevalence of chronic health conditions that affect circulation and healing. As populations in developed countries continue to age, the burden of skin ulcers on healthcare systems is expected to grow.^[1]

The location of skin ulcers also follows certain patterns. While they can theoretically develop anywhere on the body, they most commonly appear on the legs, feet, hips, back, and bottom. The legs are particularly vulnerable, with the lower leg being the most frequent site for ulcer formation. This pattern reflects the anatomical vulnerability of lower extremities to complications arising from vascular disorders, pressure, and trauma.^[1][11]

What Causes Skin Ulcers to Develop?

The fundamental cause of skin ulcers is poor blood circulation, which prevents adequate oxygen and nutrients from reaching the skin and underlying tissues. Blood flow is essential for wound healing, and when circulation becomes compromised, even minor injuries cannot heal properly. Over time, these unhealed injuries develop into chronic ulcers that persist despite the body’s natural healing processes.^[1]

Diabetes is one of the primary conditions that leads to skin ulcer formation. This disease causes elevated blood sugar levels that, over extended periods, can damage nerves throughout the body, particularly in the feet and legs. This nerve damage, called peripheral neuropathy, results in a loss of sensation in the affected areas. When people cannot feel pain or pressure in their feet and legs, they may not notice injuries when they occur. Additionally, high blood sugar levels slow down the healing process, allowing minor wounds to progress into chronic ulcers.^[1]

Atherosclerosis, also known as arteriosclerosis, occurs when arteries become narrowed due to the buildup of fatty deposits called plaque. Normally, arteries deliver oxygen-rich blood throughout the body, but when these blood vessels become clogged with plaque, blood flow to the extremities becomes restricted. This reduced blood supply means that tissues do not receive enough oxygen to remain healthy, and wounds cannot heal properly. The condition particularly affects the lower legs and feet, making these areas vulnerable to ulcer formation.^[1]

Prolonged pressure on specific areas of skin can also cause ulcers to develop, particularly in people who are bedridden, wheelchair-bound, or otherwise immobile for extended periods. When constant pressure is applied to the skin, especially over bony prominences like the tailbone, heels, or hips, blood flow to those areas becomes restricted. Skin tissues can only withstand pressure up to a certain threshold—approximately 30 to 32 millimeters of mercury. When pressure exceeds this level, circulation decreases, leading to tissue death and eventual ulcer formation. These are commonly known as pressure sores or bedsores.^[2]

Damage to the valves inside leg veins represents another important cause of skin ulcers, particularly venous skin ulcers. Veins contain one-way valves that help blood flow back toward the heart, working against gravity. When these valves become damaged, blood can back up and pool in the lower legs, causing swelling. This pooled blood may leak out of the veins and into surrounding tissue, leading to tissue breakdown and ulcer formation. This condition is called venous insufficiency.^[2][7]

Physical trauma, including cuts, burns, and other injuries, can also lead to skin ulcers, especially when the body’s normal healing processes are impaired. Wounds that fail to heal properly or become infected may progress into chronic ulcers. This is particularly true for individuals with underlying conditions that affect circulation or immune function, as their bodies struggle to repair damaged tissue effectively.^[4]

Bacterial infections can contribute to ulcer formation and complicate existing wounds. When wounds become infected with bacteria, viruses, or fungi, the healing process becomes delayed and tissue damage may worsen. Conditions such as diabetic foot ulcers or venous leg ulcers are frequently complicated by secondary infections, which further impede healing and can lead to more extensive tissue damage.^[4]

Who Is at Risk for Developing Skin Ulcers?

Several factors can increase an individual’s likelihood of developing skin ulcers. Understanding these risk factors helps people take preventive measures and seek early treatment when necessary. People who are immobile or bedridden face particularly high risk because prolonged pressure on specific body areas restricts blood flow to the skin. This includes individuals with paralysis, severe neurological disorders, or those recovering from major surgery who spend extended periods in bed or wheelchairs.^[4]

Advanced age is a significant risk factor for skin ulcer development. As people grow older, their skin undergoes changes that make it less resilient and more vulnerable to injury. The skin becomes thinner, loses elasticity, and heals more slowly. Additionally, older adults often have multiple chronic health conditions that further compromise skin health and healing capacity. The combination of these factors makes elderly individuals particularly susceptible to developing ulcers.^[4]

People with chronic health conditions face elevated risk for skin ulcers. Diabetes, peripheral artery disease, venous insufficiency, autoimmune disorders, and kidney failure all compromise skin health in various ways. These conditions may impair circulation, damage nerves, weaken the immune system, or affect the body’s ability to repair damaged tissue. The presence of any of these conditions should prompt increased vigilance for signs of skin breakdown.^[4]

Obesity increases the risk of skin ulcers through multiple mechanisms. Excess body weight places additional pressure on weight-bearing areas of the body, particularly when sitting or lying down for extended periods. This increased pressure can restrict blood flow and lead to tissue damage. Furthermore, obesity can impair circulation throughout the body, making it more difficult for wounds to heal properly. People with obesity are particularly prone to developing pressure ulcers and venous stasis ulcers.^[4]

Smoking tobacco significantly increases the risk of developing skin ulcers and impairs the healing of existing wounds. Tobacco use constricts blood vessels, reducing blood flow and oxygen delivery to tissues throughout the body. This impaired circulation makes it difficult for the body to repair damaged tissue and maintain healthy skin. Smokers who develop ulcers typically experience slower healing times and higher rates of complications compared to non-smokers.^[4][5]

A history of deep vein thrombosis, where blood clots form in the deep veins of the legs, increases the risk of venous skin ulcers. These blood clots can damage the valves in leg veins, leading to chronic venous insufficiency. Even after the clot resolves, the damaged valves may allow blood to pool in the lower legs, creating conditions favorable for ulcer development. People with a history of blood clots should monitor their legs carefully for early signs of skin changes.^[5][7]

Lack of physical activity, especially as people age, contributes to ulcer risk. Regular movement and exercise help maintain healthy circulation, preventing blood from pooling in the extremities. People who remain sedentary for long periods, particularly those with jobs requiring many hours of standing in one position, face increased risk. Walking and other forms of regular exercise promote blood flow and help prevent the development of circulation-related ulcers.^[5]

Recognizing the Different Types of Skin Ulcers

Venous skin ulcers develop as a consequence of poor blood circulation in the leg veins. These shallow wounds typically appear on the lower leg, above the ankle and below the calf, or on the sides of the lower leg. When the valves inside leg veins fail to function properly, blood cannot return efficiently to the heart and instead collects in the lower legs. This pooling causes the legs to swell, putting pressure on the skin that can eventually lead to ulcer formation. Venous ulcers often cause aching and swelling in the legs, and if they become infected, they may produce an unpleasant odor along with increased tenderness and redness.^[2][7]

Before a venous ulcer fully establishes itself, warning signs may appear. The skin over the affected area may turn dark red or purple, and it may become thick, dry, and itchy. People experiencing these early changes should seek medical attention promptly, as treating the condition before an ulcer forms completely is often more successful than treating an established wound.^[7]

Arterial ulcers, also called ischemic ulcers, occur when the arteries fail to deliver sufficient oxygen-rich blood to the lower limbs. Without an adequate oxygen supply, tissue begins to die, and ulcers develop. These ulcers typically form on the outside of the ankle, feet, and toes. Arterial ulcers are less common than venous ulcers but tend to be extremely painful. They often occur in people with artery disease and may require different treatment approaches than venous ulcers.^[2][5]

Neuropathic skin ulcers are a common complication in people with uncontrolled diabetes. Over time, elevated blood glucose levels damage nerves throughout the body, resulting in reduced or complete loss of feeling in the hands and feet. This condition, called neuropathy, affects approximately 60 to 70 percent of people with diabetes. Because individuals with neuropathy cannot feel pain or pressure normally, they may not realize they have developed an ulcer from a small cut or blister until it begins leaking fluid or becomes infected. The characteristic sign that alerts them is often a distinct odor from the infected wound.^[2]

Pressure ulcers, also known as bedsores or decubitus ulcers, result from constant pressure or friction on the skin. When pressure on the skin exceeds the threshold that tissues can tolerate, circulation becomes impaired, leading to tissue death and ulcer formation. These ulcers commonly develop over bony prominences such as the tailbone, heels, hips, elbows, and back of the head. If left untreated, pressure ulcers can extend deep into the body, causing damage to tendons, ligaments, and muscle tissue. They are particularly common in people who are bedridden or use wheelchairs.^[2][3]

A less common but serious type is the Buruli ulcer, which is caused by infection with Mycobacterium ulcerans bacteria. This infection can form large ulcers on the arms and legs. If not treated promptly and appropriately, Buruli ulcer can result in permanent physical damage and long-term disability. This type requires specific medical treatment to address the underlying bacterial infection.^[2]

Common Symptoms and Warning Signs

The appearance of skin ulcers varies depending on their severity, but they generally present as round, open sores or craters on the skin. In their initial stages, people may notice skin discoloration in the affected area. The skin might appear red and feel warm, or in individuals with darker skin tones, it may look shiny or blue. These early warning signs offer an opportunity for intervention before a full ulcer develops.^[1][2]

As ulcers progress and worsen, they take on a more crater-like appearance, with the center depressed below the surrounding skin level. The outer border often becomes raised and thick. At this stage, the ulcer may begin to weep, releasing clear fluid or blood. The severity of the ulcer determines how deep it extends—superficial ulcers affect only the outer skin layers, while severe ones can extend through multiple tissue layers, potentially exposing muscle or bone.^[1][2]

Swelling frequently accompanies skin ulcers, particularly in the area surrounding the wound. The skin near the ulcer often becomes red and tender to the touch. Many people experience itching in and around the affected area, and pain or tenderness is common, though the intensity varies depending on the ulcer type and severity. Some individuals with nerve damage may experience little or no pain, which can delay recognition of the problem.^[1][2]

Changes in skin texture provide important clues about ulcer development and progression. The skin around an ulcer may become dry and flaky, or conversely, it may appear thick and hardened. These textural changes often precede the formation of an open wound and should prompt medical evaluation. In some cases, hair loss may occur near the ulcer site, indicating compromised circulation to the area.^[2]

Discharge from the ulcer varies in character and provides information about the wound’s condition. Clear fluid or blood may weep from the ulcer as part of the body’s natural response to injury. However, yellow or green pus indicates infection, which requires immediate medical attention. An infected ulcer may also produce a foul odor, another warning sign that should not be ignored. The area around an infected ulcer typically becomes more tender, red, and swollen than before.^[1][2]

Chronic ulcers that have persisted for extended periods may cause constant pain that affects daily activities and quality of life. Patients with chronic ulcers often complain of pain both during the day and at night, interfering with sleep and normal function. The symptoms tend to worsen once infection sets in, with increased pain, development of unhealthy-looking tissue, foul odor, and breakdown of the wound rather than healing progress.^[3]

Ulcers that form on the mouth, lips, or inside the lower lip typically last from 7 to 14 days and can cause pain that affects eating and speaking. These differ from skin ulcers on other parts of the body but share the characteristic of being open sores that require time to heal.^[3]

How Healthcare Providers Diagnose Skin Ulcers

When someone presents with a suspected skin ulcer, healthcare providers begin with a thorough examination of the affected area. The doctor will look closely at the skin to confirm the presence of an ulcer and assess its characteristics. This visual examination provides essential information about the ulcer’s size, depth, location, and appearance. Based on these observations, the healthcare professional can often determine the type of ulcer and assign it a stage, which helps guide treatment decisions.^[12]

The staging system categorizes ulcers based on their severity. Stage I ulcers show redness with soft underlying tissue, representing the mildest form. In Stage II, the redness becomes more pronounced, swelling appears, and there may be blisters with loss of outer skin layers. Stage III involves necrosis (tissue death) through the deep layers of skin, with visible exposure of underlying fat. Stage IV represents the most severe form, with deeper necrosis, completely exposed fat, and possible muscle exposure. In the final stages, extensive fat loss and muscle necrosis may occur, potentially extending down to bone level with possible bone destruction and joint sepsis.^[3]

Healthcare providers also conduct a detailed medical history review, asking questions to understand the context of the ulcer’s development. They may inquire about when the ulcer first appeared, how painful it is, whether the patient has experienced ulcers before and how they were treated, what level of care assistance is available at home, and what the routine is for changing positions (particularly important for pressure ulcers). Understanding the patient’s medical conditions, current treatments, mobility level, and nutritional intake provides crucial context for developing an effective treatment plan.^[12]

Blood tests may be ordered to assess the patient’s general health status and identify underlying conditions that could be contributing to the ulcer or affecting healing. These tests can reveal issues such as diabetes, anemia, infection, or nutritional deficiencies that need to be addressed as part of comprehensive ulcer care.^[12]

Specialized imaging tests may be necessary to understand what is causing the ulcer or to evaluate the extent of tissue damage. Duplex Doppler ultrasound is commonly used to assess blood flow through the lower legs, helping doctors determine if poor circulation is contributing to the ulcer. This non-invasive test shows how well blood is moving through the veins and arteries, identifying blockages or valve problems that may require treatment.^[7]

If the ulcer does not show signs of healing within a few weeks after treatment begins, doctors may order additional tests to investigate potential complications or underlying problems. These might include more detailed imaging studies, tissue samples to check for infection, or specialized circulation tests. This thorough diagnostic approach ensures that all factors contributing to the ulcer are identified and addressed in the treatment plan.^[7]

Preventing Skin Ulcers Before They Start

For people at risk of developing skin ulcers, prevention strategies can significantly reduce the likelihood of these painful wounds forming. One of the most effective preventive measures is maintaining regular physical activity and exercise. Walking daily helps promote healthy blood circulation throughout the body, particularly in the legs, where many ulcers develop. Exercise prevents blood from pooling in the extremities and keeps tissues well-supplied with oxygen and nutrients. Even for people with limited mobility, leg exercises that involve moving feet up and down and rotating ankles can improve circulation and reduce ulcer risk.^[16]

Position changes are critically important for preventing pressure ulcers in people who use wheelchairs or spend extended time in bed. Those who use wheelchairs should try to change position every 15 minutes to relieve pressure on vulnerable areas. People who are bedridden should move or be helped to move approximately every 2 hours. Using pillows, foam cushions, specialized mattress pads, or other pressure-relieving devices helps distribute weight more evenly and reduces sustained pressure on any single area. Some of these devices are filled with water or air to provide cushioning and support.^[19]

Proper nutrition plays a vital role in preventing skin ulcers and supporting the body’s natural healing processes. A diet high in protein and adequate in calories helps maintain skin health and tissue integrity. Good protein sources include fish, chicken, and soy products. Nutritional deficiencies can weaken the skin and impair the body’s ability to prevent and heal ulcers, so ensuring adequate intake of essential nutrients is an important preventive strategy.^[17]

For people with diabetes, careful blood sugar management is essential for preventing neuropathic ulcers. Maintaining blood glucose levels within the target range recommended by healthcare providers helps prevent nerve damage that leads to loss of sensation in the feet and legs. Daily foot inspections become crucial for people with diabetes—checking for cuts, blisters, redness, or any other signs of injury allows for prompt treatment before minor wounds progress to ulcers.^[1]

Smoking cessation provides significant benefits for ulcer prevention. Because tobacco use impairs blood flow and oxygen delivery to tissues, quitting smoking improves circulation and enhances the body’s ability to maintain healthy skin and heal minor injuries before they become problematic. Similarly, maintaining a healthy weight reduces pressure on weight-bearing areas and improves overall circulation, both of which help prevent ulcer formation.^[4]

Proper skin care and injury prevention are fundamental to avoiding ulcers. Being careful not to injure the affected leg or other vulnerable areas, wearing comfortable and well-fitting footwear, and protecting the skin from trauma all contribute to prevention. For people with circulation problems or nerve damage, even minor injuries require prompt attention to prevent them from developing into more serious wounds.^[16]

How Skin Ulcers Affect the Body: Understanding the Disease Process

The development of a skin ulcer represents a breakdown in the body’s normal protective and healing mechanisms. Under healthy conditions, the skin serves as a barrier against infection and injury, and when minor damage occurs, the body initiates a complex healing process involving inflammation, new tissue formation, and tissue remodeling. This process requires adequate blood supply to deliver oxygen, nutrients, immune cells, and growth factors to the injured area. When blood circulation becomes impaired, this healing cascade cannot proceed normally.^[1]

In venous ulcers, the problem begins with dysfunction of the one-way valves inside leg veins. These valves normally prevent blood from flowing backward and help it move upward against gravity toward the heart. When valves become damaged—often due to blood clots, injury, or age-related deterioration—they fail to close properly. Blood then flows backward and pools in the lower legs, creating abnormally high pressure in the veins. This elevated pressure, called venous hypertension, causes fluid to leak from the blood vessels into surrounding tissues.^[7]

The leaked fluid contains proteins and other substances that trigger inflammation in the surrounding tissue. Over time, this chronic inflammation damages the skin and underlying structures. The skin becomes thickened, discolored, and less elastic. Small blood vessels in the area may become damaged, further compromising oxygen delivery to the tissues. Eventually, this cascade of events leads to tissue death and the formation of an open wound—the ulcer itself.^[2]

In arterial ulcers, the pathophysiology differs but the end result is similar. When arteries become narrowed by atherosclerotic plaque, less oxygen-rich blood reaches the extremities. Tissues require oxygen to maintain their normal metabolic functions and to repair daily wear and tear. Without sufficient oxygen, cells cannot function properly and eventually die. This process, called ischemia, leads to tissue breakdown and ulcer formation. The pain associated with arterial ulcers often results from this tissue oxygen deprivation, particularly when tissues are stressed by activity or elevation.^[1]

In diabetic neuropathic ulcers, high blood sugar levels over extended periods cause chemical changes in nerve fibers that impair their function. The nerves responsible for sensation gradually lose their ability to transmit pain signals effectively. Without normal pain sensation, people with diabetic neuropathy cannot feel the minor injuries, pressure points, or friction that would normally alert them to potential damage. They may walk on a foot with a small wound, continually reinjuring it without realizing it. Additionally, diabetes impairs the immune system and wound healing processes at the cellular level, making it difficult for the body to repair damage even when it is recognized and treated.^[1][2]

Pressure ulcers develop through a mechanism of sustained mechanical force on the skin and underlying tissues. When pressure exceeds the capillary closing pressure—the pressure at which tiny blood vessels collapse—blood flow to the compressed tissue stops. Without blood flow, cells are deprived of oxygen and nutrients while waste products accumulate. Initially, this causes reversible tissue damage, but if pressure continues, cells begin to die. The damage often starts in deeper tissues near bony prominences and works its way outward to the skin surface, which explains why pressure ulcers are sometimes more extensive internally than they appear on the surface.^[2]

The body’s response to tissue injury includes inflammation, which is normally part of the healing process. However, in chronic ulcers, inflammation persists abnormally, interfering with healing rather than promoting it. The prolonged inflammatory state prevents the formation of healthy new tissue and blood vessels. Chronic ulcers become stuck in an abnormal healing phase, with excessive inflammatory cells, elevated levels of destructive enzymes that break down tissue, and insufficient growth factors needed for repair. This explains why chronic ulcers can persist for months or years despite treatment efforts.^[11]

When ulcers become infected, the pathophysiology becomes even more complex. Bacteria colonizing the wound trigger additional inflammatory responses and produce toxins that damage tissue. The infection can spread from the surface wound into deeper tissues, potentially reaching muscle, tendon, or bone. In severe cases, bacteria may enter the bloodstream, causing systemic infection that affects the entire body. This progression from local wound to life-threatening systemic infection underscores why prompt recognition and treatment of infected ulcers is critically important.^[1][11]