How to treat a lump on your Achilles Tendon in 2023

Lumps on the Achilles Tendon can be worrying especially if they are painful. Thankfully there are only a few reasons for a lump on the Achilles Tendon and most can be treated without the need for surgery.

The vast majority of lumps on your Achilles are due to Achilles Tendonitis (now called Achilles Tendinopathy). Other causes may include an Achilles tendon tear if the mechanism was sudden, or very rarely a tumour (these will mostly be benign).

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In rare cases where the pain is close to the heel, conditions like insertional Achilles Tendonitis, bursitis, Haglund’s deformity or cancer (this is extremely rare) need to be considered.

This article explains how and why this lump can develop and then focuses on ways to treat a lump on the Achilles tendon.

Want to skip ahead?

What causes a lump in the middle of the Achilles?

What causes a lump at the base of the Achilles?

Other causes for a lump on the Achilles Tendon

How to treat a lump on the Achilles Tendon

Causes for a lump in the middle of the Achilles Tendon?

Photo of mid-stubstance achilles tendonitis

The Achilles tendon is the largest tendon in the body. It attaches your calf muscle to the base of your heel and is made up of thousands of string-like fibres called collagen, twisted together like a rope.

The tendon is slightly springy and is made to absorb and transfer load.

Because the tendon is so long, you can have lumps in the middle of the tendon, or towards the heel bone.

Causes for a lump in the middle of your Achilles tendon will differ depending on if the incident was sudden, or if it happened over time. Explosive movements, like charging into a sprint or jumping, can result in a partial tear of the Achilles.

If the lump slowly developed over time in the middle of your tendon and is very painful then the most common diagnoses will be Achilles Tendinopathy.

Other diagnoses will be explained further down the article.

Achilles Tendon Tears

Achilles Tendon tears are usually a result of a quick movement as mentioned above. Tears can be either partial, or full-thickness. If you develop any tears it is a good idea to get them medically assessed because they will usually result in needing a time of immobilisation in a moon boot.

A lump can develop on the Achilles tendon due to inflammation and swelling after sudden pain from an Acute tendon tear. This swelling will not be just around one point, but more broadly across the ankle. You may also notice decreased power due to pain in the Achilles tendon.

If you are diagnosed with a partial tendon tear, these are usually managed with a shorter period of time in a moonboot and then slow strengthening exercises.

Full thickness Achilles tears are more serious and may require surgery. These usually take 9-12 months to heal fully and will need extensive physiotherapy management.

In the case of full thickness tears you will usually hear an audible ‘snap’ and notice an immediate loss of power in the tendon. If this occurs it is best to seek medical advice immediately.

Mid-substance Achilles Tendinopathy

A lump will form in the middle of the Achilles tendon due to a mid-substance Achilles Tendinopathy.

In contrast to a small acute injury, lumps on the Achilles formed due to Achilles Tendinopathy generally take a long time to heal and will not fully recover with rest alone.

Achilles Tendonitis occurs because of excess load placed on the Achilles Tendon. Increased load starts a process where parts of the Achilles tendon begin to change shape and become damaged. Extra blood vessels also grow through the tendon, weakening its structure.

The symptoms of Achilles Tendonitis are pain and decreased load tolerance, as well as a lump in the Achilles Tendon. There is usually associated morning stiffness.

Lumps on the Achilles tendon due to Achilles Tendinopathy are formed by changes that happen at a microscopic level.

The Achilles Tendon fibres usually run parallel like cords in a rope. This gives the tendon great strength to resist any tension or pulling force.

Anatomy of a tendon

In Achilles Tendinopathy these tendon fibres become twisted and tangled. There is more growth of blood vessels in the affected area and there is more fluid that accumulates.

This process usually happens in one part of the tendon while the rest of the tendon remains healthy.

This will cause a lump to form on the middle of the tendon.

The good news is that these lumps can be treated and the symptoms can improve with correct management which is discussed further down.

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What causes a lump at the base of the heel?

A lump on the Achilles tendon at the base of the heel can be a result of several injuries. The most likely is insertional Achilles Tendonitis which differs slightly to mid-substance Achilles tendonitis explained above.

Other causes of a lump at the base of the heel could be Haglund’s Deformity, bursitis or posterior ankle impingement. These are all explained in more detail in our Ultimate Achilles guide.

Insertional Achilles Tendonitis

Insertional and mid-substance Achilles Tendonitis are identical except for where the symptoms are located. For Insertional Tendonitis the swelling is much lower on the tendon where it attaches into the heel.

Common symptoms for insertional Achilles tendonitis are stiffness and pain in the morning, pain and/or swelling at the base of the heel.

Insertional Tendinopathy is slightly harder to treat and tends to not respond as well, although physiotherapy is still a starting point in treatment. Surgery might be considered after a trial of 6-12 months of good physiotherapy management and still no improvement to symptoms.

Treatment is the same for both insertional and mid-substance Achilles Tendonitis and explained in more detail below.

Can the lump on Achilles get bigger?

Achilles Tendonitis is a process and if left untreated there is a chance the lump will increase in size. There is a limit to how much the lump will grow and eventually it will stop.

It is important to treat the lump as soon as possible, as the tendinopathy process will continue even if the lump has stopped growing bigger.

If not treated, there is approximately a 4% chance of the tendon rupturing for those diagnosed with Achilles Tendinopathy.

Other causes for a lump on the Achilles Tendon


Any lump that looks suspicious should be medically examined, however it is unlikely that cancer will cause this pain. It is even more unlikely if the lump is in the middle of your Achilles Tendon.

Malignant cancer in the heel is very rare for middle aged people but can affect children and adolescents and people over the age of 60.

The signs could be a general pain in the heel, and later in the presentation swelling can also be present.


There are reported cases in the literature of different tumours that can grow on the Achilles Tendon, among other places in the body.

Tumours will usually grow very slowly over a long amount of time. Any lump or bump that is of concern should be examined by a medical professional.

One example of a tumour reported on the Achilles is a Calcifying Aponeurotic Fibroma which is an uncommon tumour that can occur in children. This tumour will need medical input for treatment and will not respond with conservative management or exercise.

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How to treat a lump on the Achilles Tendon?

Research has shown again and again that passive treatments like rest or ice will not work for Achilles Tendonitis. What has shown to work is graduated loading of the Achilles Tendon.

The focus of rehabilitation should be finding a load that will challenge the tendon, without aggravating it – as too much load can be problematic.

The term load just means any force that we put through the tendon, this includes activities like everyday walking, running, jumping or any treatment like exercises/stretches.

Finding the right load can be challenging and is where physiotherapy can really help. We have done most of the work for you with our Achilles Masterclass. In this class you will be given step by step instructions on how to load the tendon in the first couple of weeks and the opportunity to join our Achilles Academy.

When loading the tendon, watch out for latent pain. Latent pain is pain that occurs after an activity, usually one hour up to a day after. If you have latent pain, it means that you have loaded the tendon too much.

General Advice

General advice would be to avoid explosive activities like sprinting or hopping.

If you are a runner, it is advisable to continue with running, but adjust the distance you run so you aren’t getting latent pain. We have given an example of a running plan in our article running with heel pain.

Begin with a program of calf raises which we have explained in detail.

Seated Calf Raises

If you need further help with finding the right amount of load, please try our Achilles Masterclass which walks you through the exact rehabilitation for Achilles Tendonitis.

It is advisable to wear the correct shoes as this can impact some people’s pain. And some people respond well to a heel lift or orthotics in their shoes.

Passive treatments aren’t recommended on their own, but they can sometimes supplement the exercises by giving temporary pain relief. You can try taping for Achilles pain, or other soft tissue techniques like massage for the calf muscle. Some patients find benefits from braces for Achilles Tendonitis as well.

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A lump in the middle of your Achilles tendon usually means Achilles Tendonitis which is treatable with exercise most of the time.

If the lump on your Achilles tendon is at the base of the heel there could be a few diagnoses. Most will respond well with treatment, however some may need medical management.

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Almushayqih Musab Hamoud, Asiri Yasser Nasser, Alshamlan Najd Abdulrahman (2020) Calcifying aponeurotic fibroma around Achilles tendon: A case report. Radiology Case Reports, Volume 15, Issue 6, Pages 753-756

Jill L. Cook, Dimitrios Stasinopoulos & Jean-Michel Brismée (2018) Insertional and mid-substance Achilles tendinopathies: eccentric training is not for everyone – updated evidence of non-surgical management, Journal of Manual & Manipulative Therapy, 26:3, 119 122, DOI: 10.1080/10669817.2018.1470302

Mascard, E., Gaspar, N., Brugières, L., Glorion, C., Pannier, S., & Gomez-Brouchet, A. (2017). Malignant tumours of the foot and ankle. EFORT open reviews2(5), 261–271.

Tanusha B. Cardoso, Tania Pizzari, Rita Kinsella, Danielle Hope, Jill L. Cook. Current trends in tendinopathy management, Best Practice & Research Clinical Rheumatology, Volume 33, Issue 1, 2019, Pages 122-140,

Youichi Yasui, Ichiro Tonogai, Andrew J. Rosenbaum, Yoshiharu Shimozono, Hirotaka Kawano, John G. Kennedy. The Risk of Achilles Tendon Rupture in the Patients with Achilles Tendinopathy: Healthcare Database Analysis in the United States (2017) Biomed Research International,