Scar tissue tightens in breast reconstruction capsular contracture when the body’s natural healing response becomes excessive around the implant. The fibrous capsule thickens due to inflammation, infection, or irritation, causing it to contract. This leads to firmness, pain, and distortion in breast shape. Increased collagen production and reduced tissue flexibility worsen the tightening, making early care and non-invasive treatments important for maintaining comfort and natural appearance.