If you use an insulin pump or wear continuous glucose monitoring (CGM) devices, you may notice certain areas of your skin becoming firm, lumpy, or less responsive to insulin over time. This is often due to scar tissue or lipohypertrophy, a common but preventable issue for people who use insulin regularly.
Understanding why scar tissue forms — and how to manage it — can improve insulin absorption, glucose control, and long-term skin health.
What Is Scar Tissue or Lipohypertrophy?
Scar tissue at insulin pump sites is often referred to as lipohypertrophy — a thickening of fatty tissue caused by repeated insulin exposure and mechanical trauma.
It may feel:
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Firm or rubbery
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Swollen or raised
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Less sensitive than surrounding skin
Injecting or infusing insulin into these areas can lead to unpredictable absorption, delayed insulin action, and unexplained high or low blood sugars.
Reference:
American Diabetes Association – Insulin Injection & Infusion Complications
https://diabetes.org/diabetes/medication-management/insulin-other-injectables/insulin-injections
Why Does Scar Tissue Form at Pump Sites?
1. Repeated Use of the Same Area
Using the same spot repeatedly doesn’t give the skin enough time to heal, leading to tissue damage.
Reference:
Association of Diabetes Care & Education Specialists (ADCES) – Infusion Site Management
https://www.adces.org/education/danatech/insulin-pumps/infusion-sets
2. Leaving Infusion Sets in Too Long
Most infusion sets should be changed every 2–3 days. Wearing them longer increases inflammation and tissue breakdown.
Reference:
Medtronic Diabetes – Infusion Set Guidelines
https://www.medtronicdiabetes.com/customer-support/infusion-set-support
3. Mechanical Trauma
Cannulas, adhesives, and frequent insertions can irritate the skin — especially if sites are placed near scars, waistbands, or areas of movement.
Reference:
Journal of Diabetes Science and Technology – Infusion Site Complications
https://journals.sagepub.com/home/dst
4. Insulin’s Effect on Fat Tissue
Insulin promotes fat growth locally, which contributes to lipohypertrophy when the same area is used repeatedly.
Reference:
National Library of Medicine – Lipohypertrophy
https://pubmed.ncbi.nlm.nih.gov/28659739/
Why Scar Tissue Is a Problem for Blood Sugar Control
Using damaged tissue can cause:
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Delayed insulin absorption
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Unexplained hyperglycemia
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Increased insulin needs
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Higher A1C levels
Many people don’t realize site issues are the cause of “random” highs.
Reference:
Diabetes Care Journal – Impact of Lipohypertrophy on Glycemic Control
https://diabetesjournals.org/care
What You Can Do to Prevent Scar Tissue
✅ Rotate Sites Properly
Use a structured rotation pattern:
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Abdomen → sides → thighs → upper buttocks
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Stay at least 1 inch from the previous site
Reference:
Cleveland Clinic – Insulin Injection Best Practices
https://health.clevelandclinic.org/insulin-injection-sites
✅ Inspect and Feel Your Skin Regularly
Check for:
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Lumps
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Firmness
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Redness
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Pain or itching
Avoid any area that doesn’t feel normal.
Reference:
ADCES – Injection Site Assessment
https://www.adces.org
✅ Change Infusion Sets on Schedule
Set reminders to change:
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Infusion sets every 2–3 days
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CGM sensors as recommended
Reference:
FDA – Insulin Pump Safety
https://www.fda.gov/medical-devices/diabetes-management-devices/insulin-pump-safety
✅ Use Proper Insertion Technique
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Clean skin thoroughly
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Let alcohol dry completely
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Avoid reinserting in irritated skin
Reference:
Mayo Clinic – Insulin Injection Tips
https://www.mayoclinic.org/diseases-conditions/diabetes/in-depth/insulin/art-20044695
Can Scar Tissue Heal?
Yes — but it takes time.
Tips for healing:
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Stop using affected areas for several months
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Rotate consistently
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Maintain good blood sugar control
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Gently massage healthy surrounding tissue
Severely damaged areas may take 6–12 months to recover.
Reference:
Diabetes Therapy Journal – Reversibility of Lipohypertrophy
https://link.springer.com/journal/13300
Travel, Daily Life & Device Care
Travel, long workdays, and busy schedules can increase the risk of site overuse. Planning ahead helps:
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Carry backup infusion sets
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Protect insulin from temperature damage
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Maintain consistent change schedules
Using a reliable medical cooler like the DISONCARE insulin cooler ensures insulin remains effective — reducing the temptation to reuse compromised sites due to supply issues.
Reference:
CDC – Insulin Storage & Handling
https://www.cdc.gov/diabetes/library/features/insulin-storage.html
When to Talk to Your Healthcare Team
Seek professional guidance if:
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Blood sugars become unpredictable
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You notice widespread lumps or pain
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Sites fail frequently
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Insulin seems less effective
A diabetes educator can help evaluate rotation patterns and insertion technique.
Reference:
American Diabetes Association – Diabetes Care Team
https://diabetes.org/tools-support/healthcare-team
Final Thoughts
✔️ Scar tissue is common — but preventable
✔️ Proper site rotation protects insulin absorption
✔️ Healthy skin improves glucose control
✔️ Good planning supports long-term device success
Your skin is part of your diabetes management system — take care of it.