The main causes of lumps below the ear are folliculitis, boils, fibro-yellow tumors and so on. 1. Folliculitis: If the skin below the ear is infected by bacteria, viruses and other pathogens that cause folliculitis, resulting in localized swelling of the skin, it can be manifested as hard lumps at the neck below the ear. 2. Boils: If the hair follicles and surrounding deep tissues at the neck below the ear are infected by pathogenic bacteria such as Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, resulting in acute suppurative inflammation, at the initial stage of the disease, the local skin will appear in the form of red, swollen, hot and painful firm nodules, i.e., small hard lumps. 3. Fibro-yellow tumor: located in the dermis and subcutaneous, mostly seen in the trunk, proximal upper arm. It is often caused by unknown trauma or itching after the development of small papules. It is coffee-colored, hard, and the border is not clear with infiltration, which is easy to be mistaken as malignant. The diameter is usually less than 1cm, and fibrosarcoma should be suspected if it increases in size. A hard lump occurs at the neck below the ear. If there is a hard lump at the neck below the ear, it may be a lymph node, etc., and you should go to the regular hospital to find out the cause of the disease in time.