Hardness around the wound after parotid adenoma surgery is usually caused by hardness and swelling after acute inflammation, scar tissue proliferation at the wound site, and thread mechanization. 1. Hard swelling after acute inflammation: acute inflammation will lead to capillary dilatation, resulting in fluid in the plasma infiltrating into the tissue interstitial space, causing hard lumps around the wound after parotid adenoma surgery. 2. Scar tissue hyperplasia at the wound site: scar tissue hyperplasia at the wound site is usually caused by keloid and external stimulation, resulting in the symptom of hard lump around the wound after parotid adenoma surgery. 3. Thread mechanization: the threads on the surgical incision undergo dissolution and absorption through the organism under long time recovery, resulting in hard lumps around the wound after parotid tumor surgery. When this condition occurs, patients are recommended to go to the hospital for examination in time, observe the body condition and target treatment under the guidance of doctors.