How Many Stages of Ulcers Do We Have? A Guide to Understanding Different Classifications

October 1, 2025 •

4 min read

The number of stages for an ulcer is not universal and depends on the ulcer's type and location. Understanding how many stages of ulcers do we have requires looking at different medical classification systems, such as those used for pressure ulcers and peptic ulcers. This article breaks down the various staging methods used in clinical practice.

Quick Summary

The number of ulcer stages varies significantly depending on the specific type of ulcer. Pressure ulcers are typically classified into four stages plus additional categories, while peptic ulcers have different classifications based on location, bleeding risk, or healing progression.

Key Points

No Single Staging System: The number of stages for an ulcer is not standardized and depends on the specific type of ulcer, such as pressure or peptic ulcers.
Pressure Ulcer Staging: Pressure sores are categorized into four numbered stages based on the depth of tissue damage, in addition to 'unstageable' and 'deep tissue injury' categories.
Peptic Ulcer Classification: These ulcers are classified differently, using systems like the Forrest classification for assessing bleeding risk or the Sakita classification for monitoring healing.
Location-Based Classification: Peptic ulcers can also be classified by their location within the stomach or duodenum, as defined by the Johnson classification system.
Diagnosis is Key: Accurate diagnosis and classification of an ulcer by a medical professional are essential for determining the correct treatment plan and assessing prognosis.
Different Causes: Pressure ulcers result from prolonged pressure, while peptic ulcers are often caused by H. pylori infection or NSAID use.

The question of how many stages of ulcers there are does not have a single, straightforward answer because 'ulcer' is a broad term encompassing different types of lesions that are classified differently. A pressure ulcer (bedsore) is staged based on the depth of tissue damage, whereas a peptic ulcer in the stomach or duodenum might be classified by its location or bleeding status. Medical professionals use specific staging systems to assess the severity, guide treatment, and predict outcomes for each type of ulcer.

Staging Pressure Ulcers (Bedsores)

Pressure ulcers, or bedsores, are injuries to the skin and underlying tissue resulting from prolonged pressure on the skin. The National Pressure Ulcer Advisory Panel (NPUAP) defines a well-established staging system for these wounds, which includes four numbered stages and two additional categories.

The Four Numbered Stages

Stage 1: Non-blanchable Redness
- The skin is intact but appears red and does not turn white (blanch) when pressed.
- For people with darker skin, the coloration may differ from the surrounding area.
- The area may be painful, firm, or warmer compared to adjacent tissue.
Stage 2: Partial-Thickness Skin Loss
- The ulcer presents as a shallow open sore with a red-pink wound bed, without slough or bruising.
- It involves the top two layers of skin (epidermis and dermis).
- This stage may also appear as an intact or ruptured serum-filled blister.
Stage 3: Full-Thickness Skin Loss
- The ulcer extends through the skin into the subcutaneous fat layer.
- Bone, tendon, or muscle are not yet exposed.
- Slough (dead tissue) may be present, and tunneling or undermining may occur.
Stage 4: Full-Thickness Skin and Tissue Loss
- This is the most severe stage, with extensive tissue destruction.
- Exposed bone, tendon, or muscle are visible.
- Slough or eschar (a thick, leathery scab) may be present on parts of the wound bed.

Other Pressure Ulcer Categories

Unstageable: The ulcer is covered by slough or eschar, obscuring the depth of the wound. A definitive stage cannot be determined until the slough or eschar is removed.
Deep Tissue Pressure Injury: This category describes a localized area of discolored intact skin (purple or maroon) or a blood-filled blister due to damage of the underlying soft tissue. The area may feel boggy or firmer than surrounding tissue.

Classifications for Peptic Ulcers

Peptic ulcers are open sores that develop on the inside lining of the stomach (gastric ulcers) or the upper portion of the small intestine (duodenal ulcers). Their staging is based on different criteria than pressure ulcers.

Forrest Classification for Bleeding Peptic Ulcers

This is a widely used system for classifying ulcers with recent or active bleeding, based on endoscopic findings. It helps determine the risk of rebleeding.

Forrest 1: Active bleeding (1a: spurting, 1b: oozing).
Forrest 2: Signs of recent hemorrhage but not actively bleeding (2a: visible vessel, 2b: adherent clot, 2c: flat pigmented spot).
Forrest 3: Lesions without active bleeding or signs of recent hemorrhage (clean base).

Sakita Classification for Gastric Ulcer Healing

An older but still relevant system for assessing the healing process of gastric ulcers:

Initial Healing Stage: The beginning of the healing process.
Proliferative Healing Stage: More significant healing takes place.
Palisade Scar Stage: A red scar forms.
Cobblestone Scar Stage: The final, white scar stage, indicating full healing.

Johnson Classification Based on Location

This classification categorizes gastric ulcers based on their location, which can help determine the likely cause and treatment approach.

Type 1: Ulcer located in the body of the stomach.
Type 2: Combined gastric and duodenal ulcers.
Type 3: Ulcer located near the pylorus, at the stomach's exit.
Type 4: Ulcer located high on the lesser curvature of the stomach.
Type 5: Ulcers occurring throughout the stomach, often related to NSAID use.

Comparison of Pressure Ulcer and Peptic Ulcer Classification


Feature	Pressure Ulcers (Bedsores)	Peptic Ulcers
Classification System	NPUAP Staging System	Multiple systems (e.g., Forrest for bleeding, Sakita for healing)
Staging Basis	Depth of tissue damage from pressure	Bleeding status, location, or healing progression
Number of Stages	Four numbered stages plus two other categories	Varies by system; e.g., three main bleeding classifications, four healing stages
Underlying Cause	Prolonged pressure, friction, and shear forces	H. pylori infection, NSAID use, excessive acid secretion
Location	Typically over bony prominences (heels, hips, tailbone)	Stomach or duodenum (first part of the small intestine)

Conclusion: The Number of Stages Depends on the Ulcer Type

In conclusion, the number of stages for an ulcer is not a universal constant but a variable that depends entirely on the type of ulcer being diagnosed. For pressure ulcers, a standard four-stage system plus additional classifications is used to categorize severity based on the depth of tissue damage. Conversely, peptic ulcers are classified by various methods, such as the Forrest classification for bleeding, the Sakita classification for healing, or the Johnson classification for location. Understanding the specific context and the type of ulcer is crucial for proper diagnosis, treatment, and communication with healthcare providers. Consulting a medical professional for an accurate diagnosis is the most important step if you suspect an ulcer. For more in-depth information on pressure ulcer classification, you can visit the European Pressure Ulcer Advisory Panel's website.

European Pressure Ulcer Advisory Panel

Frequently Asked Questions

The four main stages of pressure ulcers are Stage 1 (intact skin with non-blanchable redness), Stage 2 (partial-thickness skin loss), Stage 3 (full-thickness skin loss), and Stage 4 (full-thickness tissue loss with exposed bone or muscle).

A bleeding peptic ulcer is typically classified using the Forrest classification system. This system categorizes the ulcer based on the appearance during an endoscopy, indicating whether there is active bleeding, signs of recent bleeding, or no signs of bleeding.

Not necessarily. An unstageable ulcer means the depth of the wound is obscured by dead tissue (slough or eschar), preventing a true assessment. While the wound can be quite severe, its specific stage cannot be determined until the dead tissue is removed.

Yes, an ulcer can change stages. As an ulcer heals, it does not reverse stages. For example, a healing Stage 3 pressure ulcer becomes a healing Stage 3, not a Stage 2. However, if an ulcer worsens, its stage can advance.

The primary difference is their location. A gastric ulcer is found in the lining of the stomach, while a duodenal ulcer is located in the duodenum, the upper part of the small intestine.

Stress ulcers, a type of peptic ulcer, don't have a separate staging system but can be classified using endoscopic criteria like the Forrest classification if bleeding occurs.

The first sign of a pressure ulcer is Stage 1, which is intact skin with localized, non-blanchable redness, often over a bony prominence. The area may also feel painful, warm, or firm.