Why Is There A Lump On My Achilles Tendon?

The Achilles tendon is one of the strongest in the body. But it can also be one of the places where aches are noticeable and can affect how you move around.

In some cases, there is more than just pain in your Achilles, there is actually a bump!

You may notice this if your shoes don’t fit, or if you have pain or swelling on your Achilles.

But how do you know if it’s a problem or something to worry about?

In this article, we’ll discuss some possible reasons why there is a lump on your Achilles tendon and what you should do about it.

What Do the Achilles Tendons Do?

The Achilles is a thick, strong tendon that connects your calf muscles to your heel bone.

It acts like a strong spring, absorbing and transferring the load from the calf muscles to the heel. It also stores and returns energy to the calf muscles when you walk or run.

When the calf muscles contract, they pull on the Achilles tendon, which pulls your foot downwards. This movement then allows you to push off the ground when you run, walk, and jump.

What’s the Difference Between Tendonitis and Tendonosis?

It’s easy to assume that you have tendinitis, as both tendinosis and tendinitis share pain as a symptom.

But it’s important to be aware of the differences, as tendonosis is more serious than tendinitis.

Achilles Tendinitis

Tendinitis is an acute condition where the Achilles tendon becomes inflamed. You’ll also notice pain, swelling, warmth, and redness around the tendon.

The inflammation of tendinitis is often caused by overuse of the tendon, when it’s placed under excessive strain. With that being said, even mild cases of Achilles tendinitis can take up to 6 weeks to several months to fully heal.

If left untreated, or if you continue to place the tendon under excessive, repeated strain, it will lead to Achilles tendinosis.

Achilles Tendinosis

Tendinosis is a chronic, persistent, or recurring condition, where tiny tears develop in the tendon.

It develops over time due to overuse, not allowing the tendon sufficient time to heal, and repeated injury of the tendon.

This causes microtears around or within the tendon, which leads to the tendon becoming weak while the scar tissue thickens as it tries to rebuild and repair the tendon.

You may notice that the tendon has become thicker or that you’ve developed a painful lump on your Achilles tendon. There will also be pain or tenderness around the Achilles tendon.

There may be weakness or pain when walking as you try to push-off from the toes.

You may find that the tendon feels stiff, especially in the morning or that you have a reduced range of motion in the ankle. Unlike Achilles tendinitis, there will be no inflammation, redness, or warmth of the surrounding soft tissues.

In some cases, the Achilles tendon may have a partial tear or a complete tear—rupture—which can cause a lump to form.

Unlike a complete tear, which causes pain and an instant loss of muscle activation, a partial tear of the tendon may or may not present any symptoms.

What Does a Complete Rupture Cause?

There will be a sudden, sharp pain in the back of your calf or ankle if you’ve ruptured your Achilles tendon. It may feel like someone has hit you with a bat, and you may even hear a snapping or popping sound when the rupture occurs.

While you may still be able to walk, you won’t be able to bend your foot downwards or stand on your toes of the affected leg. This will make walking or standing difficult and painful.

There can be severe swelling or bruising on the back of your leg between the calf and ankle, near the heel. The pain can subside into a constant, dull ache in the back of the ankle or calf.

A lump can form on the back of the Achilles tendon, just above where it attaches to the heel bone.

Achilles Tendon Tears

You may notice that a lump forms on your Achilles tendon after an acute tendon tear due to the inflammation and swelling. The swelling can occur across the ankle, and it won’t be localized around one point.

It may be difficult to walk due to the pain, and you’ll notice that your calf feels weak. You may notice that it feels stiff or like the muscles are in a spasm.

It can take between 2 and 12 weeks for a partially torn Achilles tendon to heal, depending on the severity of the injury.

Mid-Substance Achilles Tendinopathy

If the lump has developed slowly in the middle of your Achilles tendon, then there’s a good possibility that you’ll be diagnosed with mid-substance Achilles tendinopathy.

This is often caused when the tendon is placed under excessive strain, and it’s loaded beyond its capacity. The tendon starts to change shape, becoming thick, painful, and inflamed within the middle of the tendon, not where it attaches to the heel.

Unlike when a lump develops from an acute injury, lumps that are caused by Achilles tendinopathy take longer to heal. They’re also not healed by rest alone.

Can the Lump on Achilles Get Bigger?

Yes, the lump on the Achilles can increase in size, especially if it’s left untreated. While the developing lump is a process, there’s a limit on how big the lump can grow, and it will eventually stop.

As soon as you notice the lump, you should start treating it. While the lump will stop getting bigger, the tendinopathy process will continue.

Depending on the severity of the tendinopathy, recovery can be slow, and a combination of treatment plans can be used to allow it to fully heal.

Treatment and Tips

One of the best ways to get rid of the lump and help your Achilles tendon to heal is to reduce the load on the tendon. This means reducing the amount of work that your tendon does on a daily basis.

Either limit or avoid any activities that can aggravate the condition, like walking, running, and jumping. Avoid stretches that load or place strain on the tendon, such as heel raises, stair stretching, or hanging stretches.

You may have to switch your training activities to low-impact activities, like cycling, swimming, or aqua jogging. This will allow your Achilles to heal while you maintain your fitness.

To reduce the load on the Achilles, you can use a heel lift or orthotic insoles. Make sure that you’re wearing shoes that support your foot shape and gait.

The best shoes for Achilles tendonitis have a heel-to-toe drop of 8 to 12 mm. This will reduce the pressure that’s placed on the tendon. It should also provide excellent ankle support to prevent any lateral movement of the foot.

Apply ice to the affected area for 10 to 20 minutes while there’s pain and swelling. You can also massage the area with an ice pack, as this will help alleviate the pain and reduce swelling.

When you’re sitting or driving, be aware of your foot’s posture, as you don’t want to inadvertently place it under pressure.


To prevent Achilles tendonitis, you should incorporate strength and stretch exercises for the calves, Achilles, and feet. This should include eccentric heel raises, isometric, isotonic, and plyometric exercises.

This can include exercises like:

  • Achilles tendon holds
  • Single leg hop
  • Box jumping

Make sure to include stretching into both your warm-up and cool-down routines, as an inflexible Achilles tendon is more prone to injury.

Gradually increase the intensity and frequency of your activities. But if you do have any soreness after intense activity, make sure to follow the RICE principle.


Rest and give your tendon time to recover. Once the pain has subsided, then you can slowly begin with your activities.

Gradually increase the intensity of your activities. If you notice any pain during your activity, stop what you are doing.


Apply ice to the painful area, as this will help to alleviate the pain and reduce the swelling.

You can apply an ice pack to the area for 10 to 20 minutes several times a day.

Wrap the ice pack in a towel, as this will prevent the pack from coming into direct contact with your skin. This will prevent skin irritation and frostbite.


Use a compression bandage to wrap the sore foot and ankle. This will help to reduce pain and swelling and promote healing.

Start by the toes and work your way up to the ankle and leg when applying the compression bandage.

The compression bandage should have a snug feel, but it shouldn’t be too tight. The compression bandage is too tight if you experience an increase in pain, numbness, or tingling.


Elevate your foot while sitting or lying down by using pillows, so that your foot is above your heart level.

This will help to reduce the swelling and is also an excellent time to apply ice.

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