What is the difference between acute and chronic tendinopathy?

Acute tendinopathy refers to short-term inflammation in the tendon ("tendinitis") usually brought on by sudden overload, trauma, or repetitive stress, while chronic tendinopathy describes a longer-term, degenerative process ("tendinosis") where the tendon undergoes structural changes with minimal active inflammation.

Acute Tendinopathy

• Pathology: Primarily inflammatory, with swelling, redness (erythema), and tenderness resulting from microtrauma, sometimes following a recent spike in activity or direct injury.

• Time course: Symptoms develop rapidly and are often directly linked with specific overload events or trauma.

• Symptoms: Localised pain, swelling, heat, and pain with movement or stretching are typical; function may be noticeably impaired during acute flares.

• Treatment: Rest, anti-inflammatories (NSAIDs), ice, and brief activity modification are usually recommended to control inflammation and allow initial healing.

Chronic Tendinopathy

• Pathology: Structural degeneration ("tendinosis") with collagen breakdown, thickening (neovascularisation), and less capacity for healing; inflammation is minimal or absent.

• Time course: Symptoms persist for weeks to months, often beginning insidiously or after repeated episodes of acute tendinopathy.

• Symptoms: Aching pain is deeper and often less directly linked to movement; there is reduced swelling, but persistent tenderness and sometimes functional limitation.

• Treatment: Focuses on long-term rehabilitation—progressive loading exercises, tendon strengthening, and lifestyle/activity modification. Anti-inflammatory treatments usually have limited benefit.

Key Differences Table

Feature	Acute Tendinopathy	Chronic Tendinopathy
Main pathology	Inflammation	Degeneration
Onset	Sudden/rapid	Gradual, persistent
Symptoms	Swelling, heat, tenderness	Aching pain, less swelling
Treatment focus	Anti-inflammatory/rest	Rehab/loading
Healing capacity	High (if managed early)	Reduced, often months-long

Acute tendinopathy involves rapid-onset inflammation; chronic tendinopathy is a slow, often irreversible degenerative condition—each requires different diagnostic approaches and treatment protocols for optimal recovery.