Hi Dr. Segler,

I've had this blister on my heel for the past three days and it has gotten slightly larger.  I'm wondering if I should allow more time for it to heal or pop, drain, etc?  What's the fastest way to get it healed?

Ryan M. 
San Francisco, CA


Hello Ryan,

A blister on the inside of the heel can be painful when running or even walking.  If you are currently training for a marathon, the last thing you want to do is stop running just because you have a blister on your heel.  But obviously the blister has to stop getting bigger before it is going to heal.

There are only a couple of reasons that a blister continues to get bigger.

1. Friction. If you are continuing to rub the inside of the heel in the same way that cause the blister to form in the first place, the blister will continue to get bigger.

2. Compression. If you repeatedly press on the blister,  the fluid with in the blessed blister will try to disperse outward. Since the fluid is all contained inside the blister, this will continue to separate the layers of the skin from the pressure applied to the blister when the fluid tries to move. This causes the blister to continue to enlarge.

The redness at the border of blister tells me that the fluid is being compressed and further separating the layers of the skin (indicated by red arrows). This of course hurts and makes the heel blister bigger.

If you pop or drain the blister, it will increase the risk of infection. If you pop (or drain) the blister it will feel slightly better in the short term, but it might take slightly longer to completely heal.  As long as all of the irritation to the blister is removed, your body will resorb the blister fluid and heal the blister.

The blister in these images appears to be flat enough that it could be offloaded with some simple pads that could be obtained from a local pharmacy.  The idea is to place felt pads around the blister. By removing the pressure that is being applied to the blister when you walk, it will stop enlarging and it will start to calm down.

If a pad is applied to the heel, it will place all of the pressure around the blister, instead of on the blister. This will significantly decrease both the compression and friction of the blister.  If the oval pads that you find at the pharmacy are not large enough, you can simply cut two of them in half and then apply two separate half-oval pads to completely surround and protect the blister.

Here is an image of the proper pad placement with the red area indicating a blister:

Once the blister has completely healed your next task will be to identify the cause of the blister.  Obviously will not want this to happen again. If you have just gotten a new pair of shoes you want to make sure to break and then more gradually the next time. If your shoes were to loose, obviously want to tie them slightly tighter so that your heel isn't sliding around inside the running shoe. And if the blister happened after running a race (where you were dumping water on your head to stay cool) or from running in the rain, you want to make sure that you avoid getting your feet as wet the next time.

Heal that heel fast so that you can get back to running!

Dr. Christopher Segler, DPM is a runner, 11-time Ironman triathlon finisher and is Board Certified,  American Board of Podiatric Medicine.  His practice is limited to runners, triathletes and other active young adults. He travels frequently lecturing to other physicians at podiatry conferences about the treatment of complicated running injuries.  He performs remote consultations for runners all over the world via telephone and Skype. He also sees patients in person in both San Francisco, CA and Houston, TX.  If you have a question about a running injury that doesn't seem to be getting better, you can reach him directly at 713-489-7674. 
8/25/2013 10:15:18 pm

Excellent response and explanation!


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