What is Achilles tendonitis and how is it different from heel bursitis? 

Achilles tendonitis and heel bursitis are two distinct conditions that cause pain at the back of the ankle and heel. While they often occur together due to their close anatomical proximity, they involve different types of soft tissue and require specific management strategies. Achilles tendonitis is an overuse injury of the thick tendon that connects your calf muscles to your heel bone, whereas heel bursitis involves the inflammation of the fluid filled sacs that cushion the joint. Distinguishing between the two is a vital step in following the correct NHS-recommended recovery path and ensuring long term joint health. 

What We’ll Discuss in This Article 

• The anatomical structure of the Achilles tendon and the heel bursae. 

• Clinical definitions and causes of Achilles tendonitis. 

• The specific nature of retrocalcaneal and superficial heel bursitis. 

• Identifying key differences in pain location and triggers. 

• How footwear and activity levels impact both conditions. 

• Standard NHS and NICE management for heel and ankle recovery. 

Understanding Achilles tendonitis 

Achilles tendonitis is the inflammation or irritation of the Achilles tendon, which is the largest and strongest tendon in the human body. This tendon is responsible for lifting the heel off the ground when you walk, run, or jump. Tendonitis typically develops when the load placed on the tendon exceeds its ability to repair itself, leading to microscopic tears in the collagen fibres. According to NHS information on Achilles tendonitis, the pain is usually felt two to six centimetres above the heel bone and is often accompanied by significant stiffness in the morning. 

Defining heel bursitis 

Heel bursitis involves the inflammation of one of the two bursa sacs located at the back of the heel. The most common form is retrocalcaneal bursitis, which occurs in the bursa situated between the heel bone and the Achilles tendon. There is also a superficial bursa located between the skin and the tendon. These sacs are designed to reduce friction, but they can become swollen and painful if they are compressed by tight footwear or repetitive movement. Unlike tendonitis, which is a structural issue with the mover of the joint, bursitis is an issue with the joint’s cushioning system. 

Key differences in pain location 

One of the most effective ways to tell these conditions apart is by pinpointing exactly where the pain is felt. In Achilles tendonitis, the tenderness is usually located a few centimetres above where the tendon meets the heel bone, often in the mid-portion of the tendon. In contrast, retrocalcaneal bursitis pain is felt deeper and directly at the back of the heel bone. If you have superficial bursitis, you may notice a visible, red, and tender lump on the very back of the heel, often caused by the rubbing of a shoe counter. 

Feature	Achilles Tendonitis	Heel Bursitis
Primary Tissue	Achilles tendon (collagen fibers)	Retrocalcaneal or superficial bursa
Pain Location	2 to 6cm above the heel bone	Directly at the back of the heel bone
Visible Signs	Thickening of the tendon	Often a visible, red, squishy lump
Main Trigger	Forceful jumping or running	Direct pressure or tight footwear

How the pain responds to movement 

The way your pain reacts to physical activity can provide further clues for identification. Achilles tendonitis pain often follows a pattern where it is very stiff in the morning, improves slightly as you warm up, but then returns with a sharp, stabbing intensity during high impact activities like sprinting. Heel bursitis pain is often more constant and is specifically aggravated by direct pressure. If your pain is triggered simply by the back of your shoe touching your heel, or if you feel a deep throb when you flex your foot upward, it is highly likely that the bursa is the primary source of the inflammation. 

Shared risks and the ‘Haglund’s deformity’ 

In the UK, clinicians frequently see these conditions occurring simultaneously, a situation often linked to a Haglund’s deformity. This is a bony enlargement on the back of the heel bone that can develop over time. This ‘pump bump’ can physically rub against the Achilles tendon, leading to tendonitis, while also compressing the bursa, leading to bursitis. Shared risk factors for both issues include a sudden increase in training intensity, running on hard or uneven surfaces, and wearing unsupportive or excessively tight footwear. NICE clinical standards for heel pain suggest that addressing these biomechanical triggers is essential for long term relief. 

Management and recovery strategies 

Management for both Achilles tendonitis and heel bursitis begins with the PRICE method to settle the initial flare up. For bursitis, the most important step is removing the source of pressure, which may involve changing your footwear or using heel pads. For tendonitis, the focus is on eccentric strengthening exercises, which help the tendon fibres to remodel and become more resilient to load. In the UK, a physiotherapist will often combine these approaches, using gentle stretching for the calf muscles to reduce the overall tension on the back of the heel, thereby relieving both the tendon and the bursa. 

Conclusion 

While Achilles tendonitis and heel bursitis both cause pain at the back of the ankle, they affect different tissues and respond to different triggers. Tendonitis is an overuse injury of the tendon itself, while bursitis is the inflammation of the protective fluid sacs. Most cases of both conditions can be managed successfully with rest, ice, and appropriate changes to footwear and activity levels. If you experience severe, sudden, or worsening symptoms, call 999 immediately. 

Authority Snapshot 

This article examines the clinical differences between common heel and ankle conditions to help patients identify and manage their symptoms effectively. It has been written by the MyPatientAdvice Medical Writing/Research Team and reviewed by Dr. Rebecca Fernandez to ensure clinical accuracy. The information provided is strictly aligned with the current NHS and NICE protocols for managing musculoskeletal and soft tissue injuries in the United Kingdom.