Most people know that living with obesity increases the risk of health conditions like type 2 diabetes and hypertension (high blood pressure). But did you know that obesity can affect your skin health too? People with class 3 obesity — typically defined as having a body mass index (BMI) of 40 or higher — may notice unexpected skin irritation and other changes in how their skin looks or feels.

Skin conditions have sparked discussion on MyObesityTeam, with members sharing their symptoms. “Does anyone else have rashes where the excess skin rubs against each other?” questioned one member.

Another said, “For the last three years, I have suffered from chronic itching and skin yeast infections.”

If you suspect a skin issue may be connected to your class 3 obesity, you could be right. This article explains several skin conditions linked to obesity and why they may occur.

Class 3 Obesity and Your Skin Health

Just as the causes behind class 3 obesity are complex, class 3 obesity skin conditions can affect your skin in complicated ways. If you have multiple skin conditions with obesity, they may be unrelated to each other.

Changes in Skin Structure

As your body size increases, your skin stretches and adapts. These changes can make your skin more prone to irritation, infections, and other conditions.

Here are a few ways skin structure can change in people with class 3 obesity:

• More folds from increased subcutaneous fat (the layer of fat under your skin), which can trap moisture and increase sweating
• Lower collagen production, which affects how well your skin heals and how firm it feels
• Reduced blood and lymphatic circulation, which can slow healing and increase the risk of infection
• Increased oil production from your skin’s sebaceous (oil) glands
• A weakened skin barrier, which can lead to dry skin and moisture loss
• Stretching of the skin, which may cause discomfort or visible changes over time

Change in How Your Body Operates

Some skin issues aren’t just caused by changes to your skin itself. They also reflect how your body functions differently with class 3 obesity.

Common factors that may lead to skin conditions include:

• Increased pressure on the feet due to added weight, which can lead to skin breakdown
• Reduced nerve sensitivity, especially in the lower body
• Friction in areas where skin rubs together, such as the thighs, underarms, or under the belly

In some cases, skin problems may be more closely linked to related conditions like type 2 diabetes or metabolic syndrome, rather than to obesity alone.

5 Common Skin Manifestations of Obesity

Medical researchers now understand that obesity is a systemic condition, meaning it can affect many parts of the body, including your skin. If you’re living with obesity, especially class 3 obesity, you may notice new or worsening skin conditions that weren’t present at a lower weight.

1. Skin Tags

Skin tags (also called acrochordons) are small, soft growths that often appear in areas where skin folds or rubs together, like the armpits. They’re usually the same color as your skin and are attached by a thin stalk. Some may look like small, raised moles. These growths are noncancerous and usually harmless, but they can be surprising or concerning when you first notice them. Some people choose to have them removed by a healthcare provider for comfort or cosmetic reasons.

How Obesity Contributes

Skin tags were the most common skin condition reported in a study looking at the connection between skin issues and obesity. They’re especially common in people with class 3 obesity due to two main factors: increased skin friction and higher insulin levels.

Skin tags tend to form in areas where skin rubs together, such as the armpits or groin or under skin folds. Elevated insulin levels, often seen with insulin resistance and type 2 diabetes, can also play a role. This happens when insulin-like growth factor 1 (IGF-1) receptors in the skin — found in fibroblasts (cells that help build collagen) and keratinocytes (cells in the skin’s outer layer) — are activated. This activation can trigger extra skin cell growth, leading to the formation of skin tags.

2. Stretch Marks

Stretch marks (striae distensae) are wavy, scarlike lines that appear when your skin stretches or shrinks quickly. This rapid change can cause collagen and elastin — proteins that help keep your skin firm and flexible — to tear. Stretch marks may show up as red, pink, purple, or dark brown, depending on your natural skin color, and can feel slightly raised when they first form. Over time, they often fade and become lighter in color.

How Obesity Contributes

Stretch marks can develop with obesity as the skin becomes more stretched due to weight gain. The added tension on the skin increases the likelihood of tearing in the deeper layers. Stretch marks are most commonly seen on the thighs, breasts, buttocks, and abdomen in people living with obesity.

Interestingly, a study found that class 3 obesity was linked to lower rates of stretch marks than milder forms. About 5.5 percent of people with class 3 obesity had stretch marks, compared to 58.2 percent of people with class 1 obesity (BMI between 30.0 and 34.9) and 36.4 percent with class 2 obesity (BMI between 35 and 39.9).

3. Acanthosis Nigricans

Acanthosis nigricans is a skin condition that causes patches of darkened skin, often described as looking like brown, gray-brown, or black “stains” — depending on your natural skin tone — that don’t wash off. It can also make other skin marks appear darker than usual. These patches usually show up in body folds, such as the armpits, the neck, or under the breasts, and often feel soft or velvety to the touch.

While not dangerous on their own, these changes in skin color can signal an underlying health issue like insulin resistance or type 2 diabetes.

How Obesity Contributes

Insulin resistance — a condition that affects 70 percent to 80 percent of people living with obesity — plays a major role in acanthosis nigricans. Like with skin tags, insulin resistance triggers the activation of IGF-1 receptors in the skin. This increases skin cell production, which causes patches of skin to thicken and darken.

4. Intertrigo

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Intertrigo is an inflammatory skin condition caused by the friction and heat of skin rubbing together. Heat and moisture make it worse. It often appears red or reddish-brown and can feel itchy, raw, or even painful and burning. When moisture is trapped — from sweat or heat — it can create an ideal environment for bacterial or fungal infections to develop on top of the rash.

How Obesity Contributes

Anyone can get intertrigo, particularly in areas like the armpits, the groin, or under the breasts. However, people living with obesity may experience it in more areas due to additional skin folds, which increases the likelihood of moisture and friction.

In addition, research shows that people with obesity may have more alkaline (less acidic) skin, which can raise the risk of bacterial or fungal overgrowth. These infections can make intertrigo harder to manage.

“I’ve had my fair share of skin infections at nearly 400 pounds,” said one MyObesityTeam member in a thread about intertrigo. “It’s humbling and embarrassing to have these issues.”

5. Pressure Ulcers

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Pressure ulcers, also called bedsores, are wounds that develop when the same area of skin is under constant pressure. Over time, that pressure cuts off blood flow, damaging the skin and underlying tissue. Without relief or treatment, the skin can break down and die, making the wound difficult or even impossible to heal.

Pressure ulcers can form on any part of the body but are most common on the ankles, back, buttocks, and hips. Their appearance depends on the stage of the wound:

• Stage 1 — The skin isn’t broken but may feel warm or tender or appear darker than surrounding skin.
• Stage 2 — The skin breaks, forming a shallow wound, blister, or abrasion with a pink or red base.
• Stage 3 — The ulcer deepens into the fatty layer beneath the skin, creating a more visible and serious wound.
• Stage 4 — The most advanced stage, where the ulcer may expose muscle, tendons, or even bone.

How Obesity Contributes

Living with class 3 obesity can increase the risk of developing pressure ulcers. In one study, hospitalized individuals with class 3 obesity were twice as likely to develop pressure ulcers as those in lower weight categories. This may be due to increased pressure on skin and tissue, particularly in people with limited mobility.

For some people, especially those with type 2 diabetes, pressure ulcers may go unnoticed at first. That’s because poor circulation and reduced nerve sensitivity can dull pain or make it harder to feel skin changes.

Skin Conditions Worsened by Class 3 Obesity

Some skin conditions aren’t directly caused by obesity but may worsen or become harder to treat with class 3 obesity. These include:

• Psoriasis — A chronic skin condition that causes inflammation and thick, scaly plaques
• Hidradenitis suppurativa — A long-term condition marked by painful lumps, inflammation, and scarring, often in areas like the armpits, groin, or under the breasts
• Cellulite — A natural skin texture with dimpling or puckering, which may be more noticeable with increased fat storage or changes in skin structure

Managing and Preventing Skin Conditions

If you or a loved one is living with class 3 obesity, it’s important to talk with a healthcare provider or dermatologist about skin changes. They can help you:

• Identify skin conditions early, before they get worse
• Recommend daily hygiene and moisture control practices to reduce skin irritation
• Prescribe treatments such as antifungal creams, topical steroids, or specialized wound care
• Offer support for long-term weight management, which can help improve both skin health and overall health

Even small changes can make a difference. Taking care of your skin and getting support from your care team can help you feel more comfortable and in control of your health.

Talk With Others Who Understand

MyObesityTeam is the social network for people with obesity and their loved ones. On MyObesityTeam, more than 57,000 members come together to ask questions, give advice, and share their stories with others who understand life with obesity.

Do you have skin conditions with class 3 obesity? How have you managed your skin health? Share your experience in the comments below, or start a conversation by posting on your Activities page.