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Foot/Leg Blisters: Diabetes or Water Retention?

Patty has advanced degrees in preventive medicine and health psychology, with 35 years of work in allergy and other autoimmune treatment.

How are your legs today—smooth and feeling good, or achy and blistered?

How are your legs today—smooth and feeling good, or achy and blistered?

Water Retention vs. Diabetic Blisters on Legs

A number of medical patients confuse the symptoms of water retention (also known as fluid retention or edema) with the appearance of chronic diabetic skin blisters. Misunderstandings of the differences between the two conditions can cause undue anxiety in patients and their caregivers.

In simple terms, water retention happens inside the body cavities and tissues to cause swelling of such areas as joints and limbs. In contrast, diabetic blisters occur on the outside surface of the body to cause raised areas filled with liquid.

Disclaimer: The following information is intended to provide a general overview. It should not be used for an official diagnosis or substituted for the expertise of a licensed healthcare practitioner. Please see your medical provider for complete diagnosis and treatment.

Foot, leg, and ankle swelling are the painless swelling of the feet and ankles as a common problem, especially among older people.

— US National Library of Medicine; Medline Plus, Article 003104

What Is Water Retention?

Fluid retention, or edema, and diabetic blisters are different in a number of ways. The first difference is that edema occurs inside body cavities or tissues, while diabetic blisters appear on the skin, outside of the body where you can see them.

Edema does not cause blisters on the skin, but it can cause swelling below the skin layers, inside other tissues and body cavities. This swelling can stretch the skin above the edema and make it look shiny (please see photos above).

Patients can confuse edema with blisters associated with untreated and uncontrolled or poorly controlled blood glucose levels in the chronic varieties of type I and type II diabetes and even hypoglycemia. Pre-diabetes and gestational diabetes are temporary and not likely to produce blisters.

In some cases, a patient might feel it more socially acceptable and less embarrassing to attribute diabetic blisters to "retaining water", but this personal attribution can delay vital treatment. Knowing and accepting the differences between the two conditions is important and supportive family and friends can help the patient accept the correct diagnosis.

The major differences found when comparing edema with diabetic blisters are listed in the table below, with explanations.

Edema Compared With Diabetic Blisters (Bullosis Diabeticorum)

Data from the Mayo Clinic, the National Institutes of Health, The Ohio State University College of Medicine, and the American Red Cross.


DESCRIPTION: Excess body fluid, often lymph, is trapped inside body tissues or cavities.

DESCRIPTION: Raised areas of liquid-filled skin appear and can be quite large on the lower legs.

USUAL LOCATION: Arms, hands, legs, ankles, and feet. Pulmonary edmea occurs within the lungs.

USUAL LOCATION: Calves, shins, and feet. Can also appear on forearms, hands, and fingers.

USUAL CAUSES: Excessive salt ingestion, pregnancy, PMS, cardiopulmonary issues, vein damage in lower legs, lymphatic system compromise, kidney disease, cirrohsis, some medications, injuries, some cancer surgeries, long airline flights..

SUSPECTED USUAL CAUSES: Diabetics can be at higher risk for foot blisters from shoes, especially in the presence of neuropathy that causes numbness; Ultraviolet radiation exposure; possibly trauma, possibly small blood vessel disease (research is ongoing); insufficient blood glucose regulation (type I and type II diabetes and hypoglycemia).

COMPLICATIONS: Pain, stiffness, diffuclty walking (legs/feet), damage to body tissues, internal tissue scarring, increased risk of infection in affected areas.

COMPLICATIONS: Pain, staphylococcal infection that sometimes leads to amputation, bone infection near blister sites if blisters are recurring, ulceration of blisters.

What Are Diabetic Blisters (Bullosis Diabeticorum)?

Infrequently, individuals with diabetes can erupt in blisters on the hands, fingers, lower legs, and feet. Blisters even less frequently may occur elsewhere, like the forearms or thighs.

The blisters look somewhat like second-degree burn blisters and are sometimes large, but they are painless and have no redness around them. They usually heal by themselves, without scars, in about two to six weeks. The only sure treatment is to bring blood sugar levels under control (Source: Retrieved March 10, 2015).

In some cases in which glucose blood levels are not well controlled, large blisters on the legs may be opened purposely by a patient or opened accidentally by friction from clothing, shoes, or tools. Bacteria enter, and the resulting infections are painful and sometimes deadly.

Chronic diabetes can result in a number of skin conditions, according to Skin Complications: American Diabetes Association. Up to 33 percent of people with diabetes will have one of the mentioned skin disorders.

Diabetes Type I and II can cause a variety of symtpms, many of them related to the skin, including blisters.

Diabetes Type I and II can cause a variety of symtpms, many of them related to the skin, including blisters.

The American Diabetes Association states that the only sure treatment for diabetic blistering is to bring blood sugar levels under control to the advised healthy level.

Leg bandages covered by a compression bandage

Leg bandages covered by a compression bandage

Embarrassment, Denial, and Effective Treatment

Very large blisters on the lower legs and forearms can present an embarrassment to patients and their families. A temptation exists to explain away blisters as water retention. Various home treatments frequently fail, causing frustration and additional pain. A few patients pop the blisters against the advise of physicians and then suffer infected wounds or ulcerated areas.

An Example of Severe Diabetic Blisters

A former neighbor of mine aged 55, with moderate obesity, suffered a group of blisters along both calves and shins, each blister reaching three to four inches in diameter. Suffering from Type II Diabetes, she regularly used oral medications, did not want to use injected insulin, and did not test her blood sugar levels. She opened the blisters, hoping they would heal, but suffered bacterial infections.

Her physician cleaned the affected areas, applied a topical antibiotic, and wrapped the legs with gauze, applying tight elastic bandages over the gauze (Please see photo below). Unfortunately, the patient unwrapped her legs, which became reinfected. This happened several times, the last instance requiring hospitalization before she consented to accept insulin therapy. Within a few months after beginning the new therapy, her legs healed, and blisters did not reappear. Within nine months, she lost a substantial amount of weight.

Do not try wrapping your own legs at home if you have large blisters, but do see your healthcare practitioner for help.

In the United States, Bullous disease of diabetes has been reported to occur in approximately 0.5% of diabetic patients. Male patients have twice the risk as female patients.

— Maureen B Poh-Fitzpatrick, MD, Disease of Diabetes in Medscape; August 24, 2015

When in Doubt, Call a Healthcare Professional

Blisters anywhere on the body may or may not be caused by a chronic form of diabetes. Large blisters on the lower legs often prove to be just that. If you experience smaller blisters that are numerous or recurring, call a healthcare practitioner for help.


  • American Diabetes Association. (March 31, 2017). Practice Resources for Diabetes Professionals. . Retrieved from › Research & Practice
  • CDC: Diabetes. (May 14, 2015). Retrieved from
  • Grand Rounds. (2014 - 2017). The Ohio State University, Wexner Medical Center and the Diabetes and Metabolism Research Center.
  • Mutasim, Diya. (March 27, 2015). Blisters. Chapter Four. In Practical Skin Pathology; (pp 187 - 194).
  • National Diabetes Education Program; NIH. (Summer 2016). The National Institute of Diabetes and Digestive and Kidney Diseases. Continuing Education.
  • Poh-Fitzpatrick, Maureen B., MD, (August 24, 2015). Bullous Disease of Diabetes in Medscape. Retrieved from

This content is accurate and true to the best of the author’s knowledge and does not substitute for diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed health professional. Drugs, supplements, and natural remedies may have dangerous side effects. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.

Questions & Answers

Question: I have something that started out as blister on the back of one heel, didn't pop, and turned into a black spot that's very sore. What should I do?

Answer: At this point, I advise you to call your health care provider as soon as you can. He or she may want to look at it and even have you take a picture with your phone and email it to them. You might also try a walk-in clinic in a grocery store - Like the Little Clinics in Kroger grocery stores. Another option is to call the local Nurses' Hotline at your nearest hospital, providing that they have such a hotline.

© 2010 Patty Inglish MS

Comments and Experiences

Patty Inglish MS (author) from USA and Asgardia, the First Space Nation on March 13, 2018:

@Jackie - Hi and thanks for writing. Ask your doctor to be sure, but I will say that I have seen the blisters go away in a couple of friends that began taking and stuck with insulin therapy. Everyone is different. I hope you find relief very soon!

Jackie san nicolas on March 11, 2018:

Looks like mine is diabetic blisters cause its on my calves and now not on if i go back on insulin will this stop?

Patty Inglish MS (author) from USA and Asgardia, the First Space Nation on November 04, 2017:

@Vasanthi Ravi - In your case, the best treatment is to see a doctor and ask if insulin is the best treatment. The blisters may be diabetic related, or not. A doctor face-to-face can make the best decision.

Thanks for your question!

Vasanthi Ravi on November 04, 2017:

My partner has diabetic and he has a Big blister and some small blisters around it in his legs. Now only i know ,that the diabetic is the cause.

What is the treatement?

Patty Inglish MS (author) from USA and Asgardia, the First Space Nation on August 19, 2015:

A long-distance acquaintance of mine who lives alone is soon to have foot surgery to remove necrotic tissues and decayed bones. He could not feel his feet for years and could not bend over far enough to see them, preventing him from discovering open lesions and broken toes. He learned of all this when he could not put on his shoes with his long shoehorn and called the EMTs.

Patty Inglish MS (author) from USA and Asgardia, the First Space Nation on March 12, 2012:

100% TRUE AS YOU SAY! A friend began taking insulin treatment and her blisters disappeared.

Nina L James from chicago, Illinois on March 12, 2012:

Hello Patty, I'm a type 2 diabetic and those blisters are nothing to joke about. In the beginning, I've had these blisters quite frequently; they are extremely painful and bothersome. The key to keeping these blisters under control is to monitor your blood sugar levels and to take your diabetes medication as directed by your doctor. A couple of years ago, I had to have surgery to remove a large painful boil because my blood sugar levels were elevated. If not treated right away, these blisters can spread. We must take care of ourselves!!!!!!

Patty Inglish MS (author) from USA and Asgardia, the First Space Nation on January 15, 2012:

Thanks for your experiences, everyone.

Has anyone experience with Type 2 diabetics becoming violent when blood sugar dips too low? A neighbor is experiencing this and some research literature says it occurs. What if the person refuses to eat on time? It's a quandary.

kelleyward on January 15, 2012:

I'm a type 1 diabetic and high blood sugar levels even just over 140 mg/dl for 1 hour have been shown to raise cardiac enzymes associated with the development of heart disease. Blood sugar control is key. Thanks for your interesting hub!

BlissfulWriter on February 13, 2011:

High sugar levels is very damaging to the body. I try not to consume too much sugar. It is sometimes frustrating because I am unable to find things in the grocery store that doesn't have too much sugar. Many things have either added sugar or "diet" with sugar substitutes. I think manufactures knows that sugary-taste makes their products sell better and that it is somewhat addictive (so that you buy more of it). But I don't think it is as addictive as cocanie.

Hello, hello, from London, UK on February 03, 2011:

A very helpful and important information. Thank you.

Funom Theophilus Makama from Europe on October 10, 2010:

This is such an awesome hub about diabetes. Its an invaluable information for people with diabetes to know. Not only for such people but even for non-diabetic individuals too, for a good spread and proper education on diabetes. Nice hub and thanks for sharing..

Alison Graham from UK on October 09, 2010:

Thanks for all the information here. My Dad had Diabetes Type 2 so I am watchful myself as I do not want to suffer the complications he had. I did not know this about the blisters, voted up and useful.

Eiddwen from Wales on October 09, 2010:

My partner is diabetic and he has these little water blisters, however we didn't know they were related to diabeties until wa read this. I am bookmarking this one in my 'most useful' hubs.

Thank you for sharing Patty.

A brilliant and informative hub.

Take care.

Patty Inglish MS (author) from USA and Asgardia, the First Space Nation on October 08, 2010:

Well, let's all control blood sugar to the best of our abilities, get medical advice if we need it, and be supportive of diabetics. Someone once asked me if there is a required or recommended daily amount of sugar intake suggested by the US government - I had to answer "0". It's a problem with Halloween candy overflowing store shelves right now.

Seakay from Florida on October 08, 2010:

My daughter is diabetic. She is now an adult but it's still a scary thing to deal with.

Thanks for the additional information! Any time I see writings on diabetes, I'm interested!

SteveoMc from Pacific NorthWest on October 08, 2010:

Very informative. Thank you for the explanations.

Om Paramapoonya on October 07, 2010:

I'm not diabetic (yet!), but diabetes runs in my family. So I've been trying to educate myself about diabetes as much as I can. This hub is very informative and well presented. Thanks for sharing, Patty. :)

Patty Inglish MS (author) from USA and Asgardia, the First Space Nation on October 07, 2010:

Thanks, susannah42 - The blisters are particular are frustrating to sufferers and interfere with life. I'll be looking for more research in this area.

susannah42 from Florida on October 07, 2010:

Good Hub. Always looking for information about diabetes, my dad has it and I want to learn as much as I can.