A painful lump on the right side of the neck may be caused by sebaceous cysts, localized folliculitis, and inflammation of the lymph nodes. 1. Sebaceous cysts: a benign skin change formed by the gradual accumulation of sebum, usually no obvious pain symptoms, if secondary bacterial infection, may cause redness, swelling and heat pain. 2. Localized folliculitis: mainly the right side of the neck skin occurs in an acute purulent skin inflammation, most commonly seen in Staphylococcus aureus infection, early manifestations of the skin parts of redness, swelling and hot pain, with the progress of the disease may form abscesses. 3. Inflammation of lymph nodes: usually caused by inflammation of nearby tissues, such as pharyngitis, otitis externa, etc., but the touch activity is better. The right side of the neck grows a lump is very painful, there may be other causes, should be timely to the hospital, to identify the cause of the targeted treatment.