Hi, Welcome to healthcare magic. Thank you for your question. There are several causes of lumps in the neck. The most common is a lymph node. Lymph nodes are normal parts of the body s immune system, and many of them are located in the neck. They can swell up, especially when they are fighting off an infection (such as a cold or sore throat). Your feeling of raised temperature on that left side of face can be a sign of inflammation too. Sometimes, lymph nodes can swell because of cancer, though there are other signs and symptoms that should be considered. Another potential cause of a lump in the neck is a cyst under the skin. These often are hard to distinguish for a lymph node but, like lymph nodes, they are generally benign and do not need any treatment. Since you have the swelling from 3 years and it has increased in size it is best for you to have this lump looked at by a doctor. Your family doctor would be a good place to start, so I suggest that you make an appointment with them.Your doctor may ask for a few investigations to be done and if your doctor is concerned he may also decide that it needs a biopsy to confirm. I hope this answers your query. With best regards. Kampana