Causes of Pain and Burning in the Achilles Tendon

Injury to your Achilles tendon can cause pain, burning, redness, and swelling. The Achilles tendon is a thick tendon that attaches your calf muscles to your heel bone. It is crucial for walking, running, and jumping.

When the Achilles tendon is stretched beyond its limits, it becomes inflamed (tendonitis) or tears (rupture). Stress or injury to the Achilles tendon can cause discomfort that can range from a slight ache and stiffness to severe Achilles tendon pain. Over time, this can develop into a degenerative condition called tendinosis.

This article covers Achilles tendonitis, tendinosis, and rupture and how they can cause Achilles tendon pain. It will also discuss when to see a healthcare provider, what diagnosis entails, and how Achilles tendon pain can be treated and prevented.

Achilles Tendonitis

The two most common causes of Achilles tendon pain are Achilles tendonitis and Achilles tendinosis. While these conditions sound similar, they describe two different problems.

Achilles tendonitis is an inflammatory injury of the Achilles tendon. It most commonly affects athletes, particularly runners, and people who play sports like tennis that require lots of starts, stops, and turns.

If you have Achilles tendonitis, you may experience pain or burning, in addition to warmth, redness, and swelling in and around the tendon itself.

Causes of Achilles Tendonitis

More often than not, repetitive stress to the Achilles tendon is the cause of Achilles tendonitis. Rarely does an injury cause tendonitis. Some of the exercise problems that can lead to Achilles tendonitis include:

• Neglecting the warm-up routine: Achilles tendonitis can happen when people don't warm up the calf muscles before exercising, or suddenly increase how much exercise they are doing overall. The tighter the calf muscles, the more tension is placed on the Achilles tendon.
• Overdoing it: You can also get Achilles tendonitis if you try to do too much, too quickly.
• Wearing the wrong shoes: Exercising in worn-out sneakers, or in shoes that aren't designed for the activity, can cause Achilles tendonitis.
• Running and jumping: Running on hard surfaces, like concrete, and jumping often, like when playing basketball, can also irritate the Achilles tendon.

Other factors that may be triggers include:

• Cold weather training
• Misaligned feet or flat fleet
• Poor running form
• Leg length differences

Certain health conditions or medications can also increase your risk for developing Achilles tendonitis.

• Bone spurs: Sometimes, Achilles tendonitis happens when a bony growth develops on the heel or calcaneus bone at the back of the ankle. This may be a bone spur from arthritis. It also may be a Haglund's deformity caused by wearing ill-fitting shoes. The growth may rub on the Achilles and cause pain and inflammation.
• Obesity: Obesity puts pressure on the lower body, which can cause Achilles tendon pain.
• Other health problems: Certain medical conditions such as psoriasis and high blood pressure have also been linked to a higher risk of Achilles tendonitis.
• Certain medications: Fluoroquinolones are widely used medications that treat various infections including gastrointestinal, respiratory, genital and urinary, and eye infections. Research suggests tendonitis is one side effect of these medications. It tends to show up soon after you start taking the medication. Of the fluoroquinolones, ciprofloxacin seems to pose the highest risk of tendonitis.

Symptoms of Achilles Tendonitis

The pain caused by Achilles tendonitis and Achilles tendinosis is similar, but there is one key difference between the two: Achilles tendonitis causes inflammation in the tendon whereas Achilles tendinosis does not.

Signs you may have Achilles tendonitis include:

• Pain in the heel and along the length of the tendon when walking or running
• Painful and stiff Achilles tendon in the morning
• Tenderness and pain when you touch or move the tendon
• Swelling and warmth in the area
• Trouble standing on your toes
• Trouble finding comfortable shoes to fit with pain in the back of the heel

The exact site of the pain may vary. It can be felt closer to the bottom of the calf muscle, along the actual tendon, or lower down near the heel bone.

Wearing orthotics, doing light Achilles tendon stretches, and taking pain medications can help.

Achilles Tendinosis

Achilles tendinosis describes a chronic (long-term) tendon condition. It results from untreated tendonitis. With tendinosis, the collagen fibers that make up the tendon break down.

The primary symptom of Achilles tendinosis is pain. You may also experience burning in the tendon area but without warmth, redness, and swelling seen in Achilles tendonitis. That's because tendinosis is a degenerative disease, not an inflammatory one.

The causes of Achilles tendinosis are less clear. Theories include overuse, decreased blood supply and tensile strength with aging, muscle imbalance or weakness, insufficient flexibility, and more.

Achilles Tendon Rupture

Though rare, an Achilles tendon rupture can also be the cause of Achilles tendon pain. An Achilles tendon rupture happens when the tendon fibers tear and separate, either completely or in part. You may or may not need surgery depending on the extent of your injury and other health factors.

Causes of Achilles Tendon Rupture

Achilles tendon rupture can occur when a sudden force is exerted upon the tendon, which often happens with sudden pivots of the foot (e.g., when playing basketball). Even a sudden step off a curb or a simple trip can sometimes be enough to overstretch and tear the tendon.

Rupture of the Achilles tendon is often seen in athletes who aren't very consistent in their training. If you're a "weekend warrior," make sure to stretch and strengthen your calf muscles appropriately and wear good, supportive shoes.

Degeneration can also cause the Achilles tendon to rupture. Degenerative changes break down and weaken the structure of the tendon, and this weakened tissue may tear easily. Certain chronic medical conditions such as rheumatoid arthritis, lupus, gout, and diabetes can cause these changes in your Achilles tendon, making it more prone to injury.

Fluoroquinolone can also lead to tendon rupture. This injury usually occurs shortly after this class of medication is started. Of the fluoroquinolones, levofloxacin is associated with the greatest risk of tendon rupture.

Symptoms of Achilles Tendon Rupture

When the Achilles does rupture, some people hear a "pop" or "snap" along with severe heel pain. Many people feel as if someone kicked them in the back of the heel and they turn around to find that no one is behind them.

There may be a visible gap where the tendon is torn. Usually, with a tendon rupture, a person cannot walk or bear weight on their foot, although a small subset of people still can.

Self-Care

Self-care strategies can be used to treat Achilles tendonitis. They also may help in the immediate care of a possible Achilles tendon rupture.

The RICE Method

RICE stands for rest, ice, compression, and elevation.

• Try to stay off your injured leg as much as possible.
• Apply ice to reduce pain and swelling.
• Wrap the affected area with an elastic bandage.
• Keep your leg elevated above your heart.

OTC Pain Relievers

Nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin and Advil (ibuprofen) can help reduce pain and inflammation. Tylenol (acetaminophen) only treats pain. If you're not sure which OTC pain reliever to take, talk to your healthcare provider about which one is best for you.

When to See a Healthcare Provider

It's important to seek medical attention if you develop Achilles tendon pain. This may be pain and/or swelling and warmth in the back of your leg, anywhere from your heel to your calf.

Some symptoms suggest a possible Achilles tendon rupture. They include sudden, severe pain at the back of the leg and/or trouble bearing weight on it. If this happens, seek immediate medical care.

Diagnosis

A medical history and physical exam are needed to diagnose Achilles tendon pain. The physical exam may include inspecting and pressing the area around the Achilles tendon to check for pain, swelling, warmth, and physical signs of an injury. Your healthcare provider will also ask you questions about your symptoms and perform specific physical tests that help identify Achilles tendon weakness or rupture.

An X-ray may be ordered to examine the bones. This will help to identify any issues like bone spurs, degenerative damage, or fracture. Injuries to the tendon can be identified with magnetic resonance imaging (MRI) or an ultrasound.

Medical Treatments for Achilles Tendon Pain

After diagnosing your Achilles tendon pain, your healthcare provider may prescribe certain treatments, including:

• Immobilization
• Physical therapy
• Surgery
  

It can take at least two to three months for Achilles tendonitis to go away. It could take longer if you don't follow the advice you are given about stretching, wearing orthotics, and limiting certain activities. The key to healing and recovery is to stay on top of your care and follow your treatment plan from start to finish.

Support

Using ice and resting may help, but you also want to keep your tendon from moving around too much. Wrap your ankle with an elastic bandage or tape if you have Achilles tendonitis.

• Splint: For a tendon rupture, you may be given a splint to immobilize your ankle. If your injury is more severe, you may need to wear the splint until you have surgery.
• Orthotics: For both tendonitis and tendinosis, shoe orthotics can be used. These are meant to correct foot misalignments that can contribute to your tendon injury. Heel lift orthotics can reduce stress on the tendon and ease the pain. If you have a partial tendon tear and don't need surgery, a controlled ankle motion (CAM) boot with a heel lift may be recommended.
  

Surgery

An Achilles tendon rupture may need surgical repair within days of the injury. An orthopedic surgeon will suture (stitch) the two ends of the tendon back together. Full recovery can take about four months.

Whether or not you need surgery for a partial tendon tear depends on your age, medical history, your normal level of activity, and how severe the tear is.

Surgery may also be used in tendinosis to remove abnormal tissues and lesions, restore blood flow, and stimulate healing. The type of surgery will be based on the extent of the damage.

Physical Therapy

If you need surgery for an Achilles tendon rupture, physical therapy may be recommended afterward to help you regain strength and mobility. If you have a partial tendon tear, physical therapy or home exercises prevent loss of muscle strength in the foot and ankle.

Some of the physical therapy techniques that may be recommended include:

• Heavy, slow resistance is an exercise protocol involving slow, progressive, heavy-load exercise.
  
• Instrument-assisted soft tissue mobilization (IASTM) helps stimulate he body's inflammatory response, prompting the production of new collagen protein.
• Eccentric strength training is an exercise that involves raising and then slowly lowering the heel of the painful leg to help lengthen muscles.
• Deep friction massage of the muscles that attach to the Achilles tendon is also helpful.
  

Preventing Achilles Tendon Pain

People tend to ignore early warning signs and push through the pain. If your Achilles tendon is sore or aches, you need to pay attention and rest it immediately.

Prevention is possible if you try some of these strategies. For example, night splints as recommended by your provider can help if you have Achilles tendonitis.

• Stretching: Stretching before you exercise will help you to avoid Achilles tendon pain and injury. Warm up with an Achilles tendon stretch, a calf stretch, or a plantar fascia stretch. Make sure to begin exercise slowly.
• Strengthening: Eccentric training may help strengthen the Achilles tendon, as well as the muscles it connects (the gastrocnemius and soleus muscles).

Other tips that may help to prevent an Achilles tendon injury include:

• Always wear shoes that provide adequate cushioning for your heel and good arch support.
• Avoid running on hard surfaces.
• Avoid exercising outside in cold weather.
  

Summary

Tendonitis is common among athletes and results from repetitive stress. It can also stem from health conditions like obesity or a bone spur and, in rare cases, injury. If tendonitis is not treated, you may develop Achilles tendinosis, a more serious and chronic condition. People with tendinosis may need a special rehabilitation program, orthotic shoes, and lifestyle changes.

The sudden, severe pain of an Achilles tendon rupture requires immediate medical attention. A healthcare provider is likely to recommend surgery to repair the rupture as soon as possible. For any Achilles tendon pain, speak to a healthcare provider so that you can get the right diagnosis and treatment before the condition gets worse.