What Is the Achilles Tendon

The Achilles tendon is the largest and strongest tendon in the human body. Running along the back of the lower leg, it connects the calf muscles to the heel bone (calcaneus), transmitting the force generated by the calf during movement.

Walking, running, jumping, and pushing off the ground all rely on this tendon, placing it among the most consistently loaded structures in the lower limb. During physical activity, the forces passing through the Achilles tendon can reach several times a person’s body weight.

Its role in everyday weight-bearing movement means even routine activities make demands on it. When that demand consistently exceeds what the tendon can handle over time, gradual wear and irritation can develop.

What Is the Achilles Tendon

Achilles tendonitis is usually caused by overuse or repeated stress on the tendon rather than a single injury. Common contributing factors include:

• Sudden increase in activity or training intensity
• Tight calf muscles
• Poor foot biomechanics (such as flat feet or high arches)
• Inappropriate or worn footwear
• Repetitive walking, running, or jumping
• Returning to activity too quickly after a break
• Age-related tendon degeneration

Less common contributors

Certain medical conditions and medications have also been associated with increased tendon vulnerability:

• Some individuals taking fluoroquinolone antibiotics, including ciprofloxacin and levofloxacin, have reported tendon-related side effects. If you develop tendon pain during a course of antibiotics in this class, speak with your prescribing doctor.
• Systemic conditions including diabetes, high blood pressure, and psoriasis have each been associated with reduced tendon resilience, likely through their effects on tissue health and circulation.

Over time, repeated strain can lead to micro-tears within the tendon, causing pain and inflammation.

What Are the Symptoms of Achilles Tendinopathy

The symptoms of Achilles tendinopathy tend to develop gradually and can vary in intensity depending on the stage of the condition:

• Pain along the tendon or at the back of the heel: Typically worse in the morning or after a period of rest, often easing as the tendon warms up with gentle movement.
• Stiffness: Particularly noticeable with the first few steps after waking or following prolonged sitting.
• Swelling or thickening of the tendon: The tendon may feel visibly or noticeably thicker than usual, and pressing along it often produces tenderness.
• Pain during activity: Running, jumping, climbing stairs, or any movement requiring a strong push-off can aggravate symptoms.
• Structural changes around the tendon: A bony bump at the back of the heel may be present in insertional cases. In non-insertional cases, a soft thickening or small nodule may form along the mid-tendon.

If symptoms persist beyond a few days, a podiatrist can provide an accurate diagnosis and appropriate treatment.

What Are the Types of Achilles Tendinopathy

Achilles tendinopathy is broadly divided into two types based on where along the tendon the problem occurs:

• Insertional Achilles Tendinopathy Insertional tendinopathy develops at the junction between the Achilles tendon and the heel bone (calcaneus). Pain is felt between the Achilles and the heel, concentrated at the very back where the tendon attaches. Pressing on the bony prominence at this attachment point typically reproduces discomfort. In some cases, a bony spur or Haglund’s deformity may also be present. Unlike the mid-portion type, insertional tendinopathy can affect people across a broad age range.
• Non-insertional (Mid-portion) Achilles Tendinopathy Mid-portion tendinopathy affects the tendon roughly 2 to 6 centimetres above its attachment to the heel bone. A soft thickening or small nodule may be palpable along the tendon in this area. More commonly seen in younger, active individuals, this type is often associated with elevated training loads or sudden increases in activity.

Knowing which type you have helps your podiatrist tailor treatment effectively.

What Are the Stages of Achilles Tendon Injury

Achilles tendinopathy progresses through recognisable stages, each reflecting a change in the tendon’s structural condition:

1. Reactive / Early Stage

• Mild pain or stiffness, especially in the morning or after activity
• Symptoms often ease as the tendon warms up
• Tendon may feel slightly thickened

2. Tendon Disrepair

• Pain becomes more frequent and lasts longer
• Reduced performance and strength
• Tendon structure begins to weaken

3. Degenerative Stage

• Ongoing or constant pain
• Significant tendon thickening or nodules
• Higher risk of tendon rupture if left untreated

Early diagnosis and treatment are important to prevent progression and long-term damage.

Diagnosis of Achilles Tendonitis

When Achilles tendinitis is suspected, particularly in the presence of heel pain and tendon stiffness, a podiatrist will conduct a thorough clinical assessment to confirm the diagnosis.

Assessment typically includes:

• Detailed Medical History: Including activity levels, recent changes in training, footwear, and symptom onset
• Physical Examination: Assessing pain, tenderness, swelling, tendon thickening, range of motion, and calf muscle flexibility
• Functional Assessment: Observing walking, running mechanics, and lower limb alignment
• Palpation of the Tendon: To identify areas of tenderness, nodules, or thickening

In some cases, imaging may be recommended to confirm the diagnosis or assess the extent of tendon damage:

• Ultrasound: Commonly used to evaluate tendon thickness, inflammation, and structural changes
• MRI: May be used if a tendon tear, rupture, or severe degeneration is suspected

Accurate diagnosis helps guide appropriate treatment and reduces the risk of the condition progressing or becoming chronic.

Pain at the Back of the Heel: When Is It Achilles-Related?

Pain at the back of the heel is a common presentation in podiatry, and in many cases it points to the Achilles tendon. A few key features can help you recognise whether your symptoms are likely Achilles-related.

Location:

• Pain at the back of the Achilles heel, at the point where the tendon meets the heel bone or slightly above it, is the defining location
• Some individuals describe pain running from the Achilles tendon toward the heel, particularly when pushing off or climbing stairs
• Tenderness when pressing along the tendon or at its heel attachment point
• Mild swelling or a visible thickening along the back of the heel may be present

How the pain behaves:

• Stiffness or discomfort that is most pronounced first thing in the morning or after periods of rest
• Pain that eases with gentle movement but returns or intensifies during sustained activity such as running, stair climbing, or prolonged walking
• A gradual onset over weeks rather than a sudden occurrence

How it differs from other heel pain:

• Unlike plantar fasciitis, Achilles-related pain is not primarily felt under the heel. Discomfort is concentrated at the back and may extend upward along the tendon

If several of these features apply, a podiatrist can confirm whether the Achilles tendon is involved and advise on appropriate next steps.

Achilles Heel Pain Treatment Options

At our podiatry clinic, heel pain treatment is tailored to the severity of the condition, activity level, and underlying causes. Most cases respond well to conservative care.

Shockwave Therapy

Extracorporeal Shockwave Therapy (ESWT) is a non-invasive option used in the treatment and management of chronic Achilles tendonitis.

• Stimulates healing and blood flow
• Reduces pain and inflammation
• Helps repair damaged tendon tissue
• No injections or surgery required

Shockwave treatment may be considered for cases that have not responded to rest and conservative care alone.

Offloading with Custom Insoles

Custom foot orthotics (insoles) are often a key part of treatment.

• Reduce strain on the Achilles tendon
• Improve foot and ankle alignment
• Address biomechanical issues such as over-pronation
• Support healing while allowing you to stay active

Custom foot insoles are designed specifically for your feet and footwear to support long-term relief and help reduce the risk of recurrence.

Surgery (When Required)

Surgery is rarely needed and is usually only consider

When Do I Need to See a Doctor for Achilles Tendonitis?

If you experience ongoing heel or Achilles pain, stiffness, or swelling, particularly when symptoms worsen with activity, seeking professional assessment early is advisable. Prompt assessment and treatment may help prevent the condition from becoming chronic and can inform steps to reduce the risk of tendon rupture.=

If pain has not improved after 1 to 2 weeks of rest and self-care, a podiatrist assessment is recommended.

Seek urgent medical attention if you notice a sudden popping or snapping sensation at the back of the heel, immediate severe pain, or difficulty pushing off the foot. These may indicate an Achilles tendon rupture and require prompt assessment.

Book an Appointment

Our podiatrists in Singapore are experienced in diagnosing and treating Achilles tendonitis using evidence-based approaches. We focus on relieving pain, restoring function, and preventing future injury.

Getting the right care to treat Achilles heel pain starts with an accurate assessment. Contact our clinic today to arrange yours.