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Achilles Tendonitis - Why Your Achilles Is Swollen and How Long It Takes to Heal

An illustration of a cross section of a foot from the side, with the toes pointing left. The skin is light peach-toned, and the bones and tendons are shades of off-white, light pink, and light blue. A yellow spot is on the achilles tendon, right above the heel, and two yellow concentric circles come from the spot, as well as three yellow lightning bolts.
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Written by Laura Henry, MD.
Resident in the Department of Otolaryngology-Head & Neck Surgery at the University of Pennsylvania
Last updated June 19, 2024

Achilles tendonitis quiz

Take a quiz to find out what's causing your achilles tendonitis.

This article will review the symptoms, causes, management, and prevention of Achilles tendonitis. Symptoms of Achilles tendonitis include creaking or cracking sounds of the ankle, swelling of or hard knots in the area of the tendon, and pain and tenderness in the morning, among others.

What is Achilles tendonitis?

The Achilles tendon connects the two large muscles of the calf to the back of the heel. It is the thickest and strongest tendon in the body rightfully so, because it is required to do the highly repetitive work of raising the foot for walking, running, and other movements. However, this also leaves the Achilles vulnerable to injury, especially overuse injury.

A swollen Achilles tendon might also be called Achilles tendinitis, Achilles tendinosis, Achilles tendinopathy, Achilles tenosynovitis, heel cord tear, calcaneal tendon tear, or Achilles tendon tear.

Achilles tendonitis can be an acute or chronic condition. The term “tendonitis” implies inflammatory cells in the region of the tendon. While this may be true in acute cases of tendon overuse or tendon tear, chronic Achilles tendon pain does not usually have inflammatory cells when looked at under the microscope and is therefore referred to as “tendinopathy.” This condition is most commonly seen in athletes who produce pain through overuse of the tendon, though the condition can present in individuals with a sedentary lifestyle as well. If an Achilles tendon that is producing pain from overuse is not allowed time to rest, the chronic condition can result. This chronic condition generally results in thickening of the tendon and can continue to produce symptoms for months to years.

You should go to a retail clinic to be treated. Common treatments for this condition are rest, alternating applying heat and ice to the tendon, and wearing heel pads to raise the heel and shorten the calf muscles to reduce strain on the tendon.

Achilles tendonitis symptoms

Common characteristics of a swollen achilles

If you're experiencing a swollen Achilles, it can likely be described by the following. Most of these symptoms will be seen in athletes who have recently increased their training regimens.

  • A creaking or crackling sound when moving the ankle or pressing on the Achilles tendon
  • Swelling or hard knots of tissue in the Achilles tendon
  • Stiffness and tenderness in the heel: Especially in the morning, that gradually goes away
  • Pain with certain activities: Ankle pain will likely get worse when walking uphill, climbing stairs, or taking part in intense or prolonged exercise
  • Mild pain or an ache above the heel and in the lower leg: Especially after running or doing other physical activities
  • Acute form: This happens suddenly, with pain and difficulty walking, and then shows up as soft swelling on and pain around the tendon.
  • Chronic form: The injury eventually becomes a hardened, rubbery enlargement at the back of the ankle.
  • Inflammation: The tendon will feel very warm to the touch.

Duration of symptoms

The duration of your swollen Achilles can vary.

  • Acute form: This happens suddenly, with immediate symptoms of pain and loss of use.
  • Chronic form: This happens over time, with gradual onset of pain and difficulty moving.

Who is most often affected?

People most likely to experience a swollen Achilles include:

  • Men over the age of about 35, especially if playing amateur sports, are vulnerable.
  • Being overweight, lacking flexibility, and having weak calf muscles are all risk factors.
  • People with diabetes.

When is it most likely to occur?

Your Achilles is most likely to become irritated and swell:

  • During strenuous exercise: Acute injury often occurs when running uphill or running with sudden changes of direction, especially if the person has been overtraining for weeks or months beforehand.
  • After resting: In the chronic form, there is often pain and ankle stiffness on getting up in the morning.

Is it serious?

A swollen Achilles can vary in severity depending on the cause or extent of the injury, if applicable.

  • Not serious: A mild strain can usually be treated with ice, rest, non-steroidal anti-inflammatory drugs, and possibly physical therapy.
  • Moderately serious: A chronic condition should be seen by a medical provider and/or a physical therapist, who can determine a course of treatment and therapy.
  • Serious: An acute rupture can be very painful and cause permanent damage to the tendon, and should be seen by a medical provider right away.

Achilles tendonitis quiz

Take a quiz to find out what's causing your achilles tendonitis.

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Achilles tendonitis causes

Achilles tendonitis is most commonly seen in athletes, occurring before the age of 45 in many cases. Increasing age predisposes an individual to tendonitis because as the tendons age, the collagen within them becomes less durable, predisposing them to injury more easily. Achilles tendonitis is considered chronic if symptoms last greater than three months. This condition often becomes chronic as there are areas of the Achilles tendon with a lower blood supply, which reduces the rate at which injuries to the tendon are able to be healed.

The cause of the condition is repeated, intense strain on the Achilles tendon. The condition is more likely to occur when someone suddenly increases the amount of time spent on their feet or increases the intensity of their training regimen. Other risk factors include:

  • Initiating sports that require sudden starts and stops: Such as basketball or tennis
  • Shoe choices: A change in shoes or repeatedly wearing worn out, unsupportive shoes
  • Running up hills: This can increase the stretch on the Achilles tendon and cause injury.
  • Other leg and foot characteristics: Such as weak calf muscles, flat arches of the feet, feet that roll inwards when running (overpronation), or feet that roll outwards when running (oversupination)
  • Intense exercise regimens without stretching or warming up

Acute rupture of the Achilles tendon

A rupture of the Achilles tendon may be either partial or complete and usually happens during running or some other kind of exercise. The pain comes on suddenly, with immediate difficulty walking.

Rare and unusual causes

Cerebrotendinous Xanthomatosis is a hereditary disorder of improper cholesterol metabolism. One of the symptoms is painfully swollen Achilles tendons in both legs, with difficulty walking. This condition should be treated with medication, not surgery.

Achilles tendonitis treatments and prevention

At-home treatments for a swollen Achilles

The treatment of Achilles tendonitis is usually conservative therapy with regimented physical therapy, activity adaptation, and pain management. Tendons that are injured due to overexertion or overuse undergo biological changes and, as a result, are less able to absorb the force exerted on them with movement. To allow these biological changes to reverse, the exertion or strain on the tendon should be modified, and thus practice time may need to be reduced.

The management of acute Achilles tendonitis is as follows:

  • Avoidance of painful activities
  • Application of ice when experiencing pain
  • Seven to 10 days of non-steroidal anti-inflammatory medications
  • Taping the heel so that it is lifted: Thus reducing the extension of the tendon
  • Daily stretching
  • Braces and supports
  • Change up your routine: Rotate different forms of exercise so that you are not doing the same thing every day. Walking and swimming are especially helpful since they are low-impact and put less stress on the body.
  • Ice: Apply an ice pack or cold pack to the tendon a few times a day, especially after exercising.

The management of chronic Achilles tendonitis (>3 months) is as follows:

  • All the measures listed above for acute tendonitis
  • Rehabilitation exercises with heavy loads: The idea of this measure is to gradually strengthen the tendon and promote healing. A common exercise prescribed for Achilles tendonitis is weighted heel raises.

Prevention

Data suggests that the lifetime incidence of Achilles tendonitis is as high as 24 percent in competitive athletes There are certain risk factors for Achilles tendonitis that cannot be altered by individuals (e.g. male gender and increasing age). However, other risk factors can be mitigated in an effort to prevent tendonitis. Wearing proper footwear with adequate support, maintaining strong leg muscles, gradual increases in exercise regimens, and stretching are all generally recommended by doctors as preventative measures.

There is also a rare association between taking fluoroquinolones, a type of antibiotic, and the development of Achilles tendinopathy and tendon rupture. If this rare complication develops, it usually occurs within a week of starting the drug.

When to seek further help for Achilles tendonitis

Both athletes and non-athletes who begin experiencing pain in the Achilles tendon should consult their doctor. While this is not a medical emergency, earlier management and intervention can prevent the condition from becoming chronic. Early intervention with rest, ice, pain management, and bandaging can help prevent the tendon from thickening and developing scar tissue.

  • Severe tendon pain: You should discuss pain that interferes with walking or other activities of daily living.
  • Additional treatments: This may include surgery, injections, or acupuncture.
  • Physical therapy: A physical therapist can give you appropriate stretching and exercises, as well as other treatments that may help.
  • Podiatry referral: A foot specialist can arrange for custom-fitted shoe inserts.
  • Suspicion of cerebrotendinous xanthomatosis: The symptoms include painful, swollen Achilles tendons in both legs, as well as neurologic abnormalities such as seizures and impaired speech.

Achilles tendonitis FAQs

Should a chronic Achilles tendon injury be treated with heat or with cold?

A chronic injury is one which goes on for a long time with little improvement. Treatment with ice is most helpful when the tendon is first injured and at its most painful since cold reduces inflammation. After a few days, however, heat is more effective for reducing pain, increasing blood flow, and promoting healing.

What sort of braces or supports can help an Achilles tendon injury?

With a chronic injury, the proper brace can provide support and take some of the pressure off of the tendon. This will reduce pain and discomfort during exercise and activities of daily living. However, it is important to use the brace sparingly since constant bracing can cause weakness of the muscles and atrophy of the already-damaged tendon.

What kind of shoes can help an Achilles tendon injury?

Sports shoes with plenty of support and cushioning are best. Orthotics are inserts of foam and rubber, often custom made, that can help stabilize the position of the foot and take the strain off of the Achilles tendon. A podiatrist can advise you as to the best kind of shoe and orthotic for your particular case.

Are corticosteroid injections helpful for an Achilles tendon injury?

Corticosteroid medication such as cortisone is sometimes injected into a joint for relief of inflammation. However, such injections given directly into a tendon can cause weakening and even rupture (tearing) of the tendon. This is why corticosteroid injections are not recommended for a chronic Achilles tendon injury since this can cause it to become an acute injury.

Are there any alternative or experimental treatments available for an Achilles tendon injury?

Percutaneous repair means sutures are passed through only the skin and the tendon, instead of stitching the tendon inside an open surgical wound. This is effective and less risky. Platelet-rich plasma injections may be helpful. Massage can sometimes increase blood flow and break down scar tissue. You can discuss all of the above with your medical provider.

Questions your doctor may ask to determine Achilles tendonitis

  • How severe is your foot pain?
  • How long has your foot pain been going on?
  • Is your foot pain getting better or worse?
  • Is your foot pain constant or come-and-go?
  • Did you just suffer from a cut or wound?

Self-diagnose with our free Buoy Assistant if you answer yes on any of these questions.

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The stories shared below are not written by Buoy employees. Buoy does not endorse any of the information in these stories. Whenever you have questions or concerns about a medical condition, you should always contact your doctor or a healthcare provider.
Dr. Rothschild has been a faculty member at Brigham and Women’s Hospital where he is an Associate Professor of Medicine at Harvard Medical School. He currently practices as a hospitalist at Newton Wellesley Hospital. In 1978, Dr. Rothschild received his MD at the Medical College of Wisconsin and trained in internal medicine followed by a fellowship in critical care medicine. He also received an MP...
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References

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  5. van der Linden PD, van Puijenbroek EP, Feenstra J, et al. Tendon disorders attributed to fluoroquinolones: A study on 42 spontaneous reports in the period 1988 to 1998. Arthritis Rheum. 2001;45(3):235-9. PubMed Link