Swollen lymph nodes are frequently the outcome of a bacterial or viral illness. Swollen lymph nodes are seldom caused by malignancy. Lymph nodes, also known as lymph glands, play an important part in your body's capacity to fight infections. When you get sick, your immune system responds by trying to protect you from further infection. This response includes activating certain cells that produce antibodies which help destroy bacteria and viruses that might otherwise cause you more harm. During a fever, the body produces more heat, which can lead to hot spots on skin surfaces. The same thing happens with your body when it fights off an infection. Hot spots appear on your neck because there is a large group of lymph nodes located here. These nodes serve as centers for immune system activity. Lymph nodes are usually about the size of a grain of rice, but some may be larger or smaller. They are not always visible under the skin, but often leave marks on the chest or abdomen. The pain associated with swollen lymph nodes is due to pressure being placed on nearby nerves. People tend to worry about cancer when seeing a lymph node that is larger than normal. However, most often, these nodes are not cancerous. Some cancers do cause symptoms by causing lymph nodes to swell, but this is not common. Examples include cancer of the lung, breast, stomach, intestines, prostate, and thyroid.