The majority of soreness in the cheek and behind the ear can be related to parotid gland diseases, which can be caused by inflammation or tumor, as follows: 1. Inflammation, parotitis has a rapid onset with local redness, swelling, heat and pain, and should be checked urgently for routine blood tests, blood amylase, to clarify whether it is purulent parotitis or mumps, and also auxiliary ultrasound. 2. tumors, parotid tumors are divided into benign tumors and malignant tumors. benign tumors are painless lumps that grow slowly and can last up to 10 years; malignant tumors can be associated with pain, local numbness, facial paralysis and have a shorter duration. The examination of parotid tumor is based on ultrasound and CT examination, and surgery is the most effective treatment, while malignant tumors require adjuvant radiotherapy or chemotherapy after surgery.