I have a hard lump behind my left ear which has caused a lot of pain and has grown over the past three days. it makes me feel sick and blurs my vision?

Furuncul aka boil: Boils can occur anywhere on your skin. It is a bacterial skin infection. The common symptoms are: painful, red bump that increases in the size over a few days. Boil also can cause a fever. You can actually treat a single boil at home by applying warm compresses to relieve pain and promote natural drainage. Take some nsaids otc. If concerned or high fever see your pcp.