Table of ContentsView AllTable of ContentsWhat They AreSymptomsCausesWhen to See a ProviderDiagnosisTreatmentPrevention
Table of ContentsView All
View All
Table of Contents
What They Are
Symptoms
Causes
When to See a Provider
Diagnosis
Treatment
Prevention
Blood blisters are raised pockets of skin that contain blood. They form when an injury breaks tiny blood vessels under the skin, causing blood to pool beneath the unbroken layer.
A blood blister is similar to afriction blisteryou might get when wearing ill-fitting shoes but contains blood rather than clear liquid. The blood will initially be red but turn darker as the days pass.
Blood blisters usually disappear on their own and pose no significant health concerns. However, there are times when an evaluation is needed to rule out potentially serious causes, such as kidney failure or uncontrolled diabetes.
This article explains how to spot and treat a blood blister. It also describes how to prevent blood blisters from forming and when it is time to see a healthcare provider.
What Is a Blood Blister?
A blood blister forms when tiny blood vessels (calledcapillaries) are broken in subdermal tissues without breaking the skin. Subdermal tissues lie just beneath the middle layer of skin (called thedermis) and are rich in blood andlymph vessels.
When the skin is aggressively rubbed, pinched, or struck, a blister can form as blood and lymph fluid form a pocket beneath the top of the skin (called theepidermis). The unbroken skin acts as a barrier to germs and can protect the underlying tissues from infection.
The blood in the blister can turn from red to purple as the blood cells start to die and release oxygen.Hemoglobin, the protein that gives blood its color, turns bright red when oxygenated and purple with it is not.
As the fluid in the blister starts to dry up, the contents can become putty-like and the overlying skin can become hard and irregular.
Greg Bethmann / Getty Images
Signs and Symptoms of a Blood Blister
Symptoms of a blood blister may include:
The size and location of a blood blister can tell a lot about the cause of a blister.
Blood blisters can often be found on the hands and fingers, feet and toes, and on joints or bony areas such as the heels or balls of your feet They can also appear around or inside the mouth or lips.
Causes of Blood Blisters
While blood blisters can happen to anyone, they are common in active people (such as athletes or dancers) or people who work with their hands or spend a lot of time on their feet.
Common causes of blood blisters include:
Takinganticoagulants(“blood thinners”) can further increase the risk of blood blisters.
More serious causes of blood blisters include:
When to Visit a Healthcare Provider
Blood blisters typically heal on their own within a week. They do so as new skin grows over the injured tissues and the overlying skin is shed.
While most blood blisters are nothing to worry about, you should see a healthcare provider if you have unusual symptoms as this may be a sign of a serious medical condition.
Examples include:
If there are any doubts about the cause of a blood blister, a healthcare provider can run tests to check for signs of infections, diabetes, or medical conditions like rheumatoid arthritis. This may involve blood tests or procedures like abiopsyfor blisters that have an unusual appearance or are in unusual places, such as the brain, back, buttocks, or face.
While unlikely, a blood blister may turn out to be something else entirely, like cancer.
Blood Blister vs. Nodular Melanoma
Nodular melanoma, a type of aggressive skin cancer, is one condition often mistaken for a blood blister. This blood blister lookalike grows rapidly—typically over the course of several weeks or months—so it’s important to catch it as early as possible.
Unlike other forms of skin cancer, nodular melanomas are typically symmetrical like a blister. They are often smooth like a blood blister but can also be rougher and crusty. Nodular melanomas are often dark purplish, but they can also be flesh-toned.
Abiopsyis critical to the diagnosis. This is the only procedure that can definitively diagnose skin cancer and ensure the correct treatment.
How to Get Rid of Blood Blisters
Most of the time, a blood blister will heal on its own as long as you protect it and avoid popping or draining it.
To treat a blood blister at home you should:
Should You Pop or Drain a Blood Blister?
Though you may be tempted to pop a blood blister, experts recommend resisting the urge to do so. The layer of skin that covers the blister helps protect the underlying tissues from infection. Over time—about one to two weeks—the blister should dry up on its own.
Afterward, wash the area with soap and water, apply antibacterial cream, and cover the blister with a bandage or gauze.
Verywell / Brianna Gilmartin
Accidents happen and, even with the best of care, blood blisters can still occur. But there are a few things you can do to decrease the risk:
Summary
Blood blisters are blisters that fill with blood instead of clear fluid. They can occur when you smash a finger, wear ill-fitting shoes, or cause trauma that bursts capillaries beneath the skin. Blood blisters are easily treated and usually heal on their own without incident.
On rare occasions, blood blisters can result from a serious condition like frostbite, uncontrolled diabetes, kidney failure, rheumatoid arthritis, or rare conditions like angina bullosa hemorrhagic or leukocytoclastic vasculitis. See a healthcare provider if a blood blister develops for no reason or has an unusual appearance, location, or symptoms.
11 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Government of Victoria (Australia).Blisters.Sugerman DT.Blood thinners.JAMA. 2013;310(23):2579. doi:10.1001/jama.2013.282755Handford C, Thomas O, Imray CHE.Frostbite.Emerg Med Clin North Am. 2017;35(2):281-299. doi:10.1016/j.emc.2016.12.006.Duff M, Demidova O, Blackburn S, Shubrook J.Cutaneous manifestations of diabetes mellitus.Clin Diabetes.2015;33(1):40-8. doi:10.2337/diaclin.33.1.40Galperin TA, Cronin AJ, Leslie KS.Cutaneous manifestations of ESRD.Clin J Am Soc Nephrol. 2014;9(1):201-218. doi:10.2215/CJN.05900513Okobi OE, Evbayekha EO, Ebili U. et al.Angina bullosa hemorrhagica: a rare and interesting presentation.Cureus.2022 Mar;14(3):e23335. doi:10.7759/cureus.23335Conforti A, Di Cola I, Pavlych V, et al.Beyond the joints, the extra-articular manifestations in rheumatoid arthritis.Autoimmun Rev. 2021;20(2):102735. doi:10.1016/j.autrev.2020.102735Fraticelli P, Benfaremo D, Gabrielli A.Diagnosis and management of leukocytoclastic vasculitis.Intern Emerg Med. 2021;16(4):831-841. doi:10.1007/s11739-021-02688-xAmerican Academy of Dermatology Association (AAD).How to prevent and treat blisters.McCourt C, Dolan O, Gormley G.Malignant melanoma: a pictorial review.Ulster Med J. 2014 May;83(2):103-110.Worthing RM, Percy RL, Joslin JD.Prevention of friction blisters in outdoor pursuits: a systematic review.Wilderness Environ Med. 2017;28(2):139-149. doi:10.1016/j.wem.2017.03.007Additional ReadingInstitute For Preventive Foot Health.Causes of blisters.PathologyOutlines.com.Skin - nontumor, blistering disorders, blood blister.U.S. National Library of Medicine, Medline Plus.Blisters.
11 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Government of Victoria (Australia).Blisters.Sugerman DT.Blood thinners.JAMA. 2013;310(23):2579. doi:10.1001/jama.2013.282755Handford C, Thomas O, Imray CHE.Frostbite.Emerg Med Clin North Am. 2017;35(2):281-299. doi:10.1016/j.emc.2016.12.006.Duff M, Demidova O, Blackburn S, Shubrook J.Cutaneous manifestations of diabetes mellitus.Clin Diabetes.2015;33(1):40-8. doi:10.2337/diaclin.33.1.40Galperin TA, Cronin AJ, Leslie KS.Cutaneous manifestations of ESRD.Clin J Am Soc Nephrol. 2014;9(1):201-218. doi:10.2215/CJN.05900513Okobi OE, Evbayekha EO, Ebili U. et al.Angina bullosa hemorrhagica: a rare and interesting presentation.Cureus.2022 Mar;14(3):e23335. doi:10.7759/cureus.23335Conforti A, Di Cola I, Pavlych V, et al.Beyond the joints, the extra-articular manifestations in rheumatoid arthritis.Autoimmun Rev. 2021;20(2):102735. doi:10.1016/j.autrev.2020.102735Fraticelli P, Benfaremo D, Gabrielli A.Diagnosis and management of leukocytoclastic vasculitis.Intern Emerg Med. 2021;16(4):831-841. doi:10.1007/s11739-021-02688-xAmerican Academy of Dermatology Association (AAD).How to prevent and treat blisters.McCourt C, Dolan O, Gormley G.Malignant melanoma: a pictorial review.Ulster Med J. 2014 May;83(2):103-110.Worthing RM, Percy RL, Joslin JD.Prevention of friction blisters in outdoor pursuits: a systematic review.Wilderness Environ Med. 2017;28(2):139-149. doi:10.1016/j.wem.2017.03.007Additional ReadingInstitute For Preventive Foot Health.Causes of blisters.PathologyOutlines.com.Skin - nontumor, blistering disorders, blood blister.U.S. National Library of Medicine, Medline Plus.Blisters.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Government of Victoria (Australia).Blisters.Sugerman DT.Blood thinners.JAMA. 2013;310(23):2579. doi:10.1001/jama.2013.282755Handford C, Thomas O, Imray CHE.Frostbite.Emerg Med Clin North Am. 2017;35(2):281-299. doi:10.1016/j.emc.2016.12.006.Duff M, Demidova O, Blackburn S, Shubrook J.Cutaneous manifestations of diabetes mellitus.Clin Diabetes.2015;33(1):40-8. doi:10.2337/diaclin.33.1.40Galperin TA, Cronin AJ, Leslie KS.Cutaneous manifestations of ESRD.Clin J Am Soc Nephrol. 2014;9(1):201-218. doi:10.2215/CJN.05900513Okobi OE, Evbayekha EO, Ebili U. et al.Angina bullosa hemorrhagica: a rare and interesting presentation.Cureus.2022 Mar;14(3):e23335. doi:10.7759/cureus.23335Conforti A, Di Cola I, Pavlych V, et al.Beyond the joints, the extra-articular manifestations in rheumatoid arthritis.Autoimmun Rev. 2021;20(2):102735. doi:10.1016/j.autrev.2020.102735Fraticelli P, Benfaremo D, Gabrielli A.Diagnosis and management of leukocytoclastic vasculitis.Intern Emerg Med. 2021;16(4):831-841. doi:10.1007/s11739-021-02688-xAmerican Academy of Dermatology Association (AAD).How to prevent and treat blisters.McCourt C, Dolan O, Gormley G.Malignant melanoma: a pictorial review.Ulster Med J. 2014 May;83(2):103-110.Worthing RM, Percy RL, Joslin JD.Prevention of friction blisters in outdoor pursuits: a systematic review.Wilderness Environ Med. 2017;28(2):139-149. doi:10.1016/j.wem.2017.03.007
Government of Victoria (Australia).Blisters.
Sugerman DT.Blood thinners.JAMA. 2013;310(23):2579. doi:10.1001/jama.2013.282755
Handford C, Thomas O, Imray CHE.Frostbite.Emerg Med Clin North Am. 2017;35(2):281-299. doi:10.1016/j.emc.2016.12.006.
Duff M, Demidova O, Blackburn S, Shubrook J.Cutaneous manifestations of diabetes mellitus.Clin Diabetes.2015;33(1):40-8. doi:10.2337/diaclin.33.1.40
Galperin TA, Cronin AJ, Leslie KS.Cutaneous manifestations of ESRD.Clin J Am Soc Nephrol. 2014;9(1):201-218. doi:10.2215/CJN.05900513
Okobi OE, Evbayekha EO, Ebili U. et al.Angina bullosa hemorrhagica: a rare and interesting presentation.Cureus.2022 Mar;14(3):e23335. doi:10.7759/cureus.23335
Conforti A, Di Cola I, Pavlych V, et al.Beyond the joints, the extra-articular manifestations in rheumatoid arthritis.Autoimmun Rev. 2021;20(2):102735. doi:10.1016/j.autrev.2020.102735
Fraticelli P, Benfaremo D, Gabrielli A.Diagnosis and management of leukocytoclastic vasculitis.Intern Emerg Med. 2021;16(4):831-841. doi:10.1007/s11739-021-02688-x
American Academy of Dermatology Association (AAD).How to prevent and treat blisters.
McCourt C, Dolan O, Gormley G.Malignant melanoma: a pictorial review.Ulster Med J. 2014 May;83(2):103-110.
Worthing RM, Percy RL, Joslin JD.Prevention of friction blisters in outdoor pursuits: a systematic review.Wilderness Environ Med. 2017;28(2):139-149. doi:10.1016/j.wem.2017.03.007
Institute For Preventive Foot Health.Causes of blisters.PathologyOutlines.com.Skin - nontumor, blistering disorders, blood blister.U.S. National Library of Medicine, Medline Plus.Blisters.
Institute For Preventive Foot Health.Causes of blisters.
PathologyOutlines.com.Skin - nontumor, blistering disorders, blood blister.
U.S. National Library of Medicine, Medline Plus.Blisters.
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