Lymph nodes (or glands) are found all over the body. They are part of the body’s immune system, which is our body's very effective defence mechanism for fighting infections. Our lymph nodes are home to white blood cells, which are responsible for fighting bugs (such as bacteria and viruses) which can get into our bodies and make us feel ill. We have big groups of lymph nodes in our neck, armpits and groin. When you get an infection, such as a cold, or sore throat, or earache, or a boil on your skin, white blood cells will move in large numbers to the nodes so that they can kill the bug that is causing the infection. This causes the nodes to swell, and can sometimes be a bit uncomfortable. The nodes soon return to their normal size once the infection has gone. The vast majority of swollen lymph nodes are caused by infections. However, very rarely lymph nodes will get bigger because of other causes, such as problems with your immune system, or cancer. So, if you have noticed some enlarged glands but you feel completely well and there is no evidence that you may have an infection, it is worth seeing your doctor. It is also worth seeing your doctor if your swollen glands do not go back down within 2 or 3 weeks.