Lymph nodes are small pea or bean shaped organs that are located widely throughout the body. They are a part of the immune system and are interconnected via the lymphatic system. They act as filters protecting the body from foreign materials such as bacteria and viruses. Every lymph node in your body is home to many white blood cells called lymphocytes and macrophages. These white blood cells protect the body and cause immune responses to bacteria and viruses.
Why causes swollen lymph nodes?
You may have noticed that when you become sick that your lymph nodes swell. The lymph nodes that most people notice are those in the throat, under the arms and in the groin area. Lymph nodes swell for a number of different reasons.
The most common reason for swollen lymph nodes is bacterial or viral infection. When the body is fighting an infection the lymph nodes become hard and inflamed due to the extra production of white blood cells to fight the invading substance. Other immune cells are also circulated through the lymph nodes increasing the number of cells in the lymph nodes thus making them swell. Some bacterial and viral infections, such as mumps, attack the lymph nodes specifically. In this case the growth of the bacteria or virus also increases the size of the lymph node.
Lymph nodes may also swell if there is an infection somewhere else in the body. The swelling is again cased by the extra production of immune cells. If there is an infected wound, internal infection such as a urinary tract infection or blood infection, the lymph nodes will usually swell. The lymph nodes that are closest to the infection are the most likely to swell.
The presence of abnormal tissue or cancer in the lymph node can also cause the lymph node to appear swollen. Leukemia is the most well known form of cancer that can cause lymph nodes to become inflamed. Another type of cancer called Lymphoma attacks the lymph system specifically causing specific lymph nodes to swell.
Certain autoimmune disorders also cause the swelling of lymph nodes. Disorders such as lupus, rheumatoid arthritis, Hashimoto’s thyroiditis, or HIV cause the lymph nodes to produce more white blood cells to fight normal body cells that it perceives as a threat. These types of disorders may enlarge and inflame lymph nodes for long periods of time.