Swollen lymph nodes

The lymphatic system has two main functions. Its network of vessels, valves, ducts, nodes, and organs helps balance the body's fluid by draining excess fluid, known as lymph, from the body's tissue and returning it to the blood after filtering it. Some types of blood cells are also made in the lymph nodes. The lymphatic system also plays an important role in the body's immune system. Infection, even a trivial infection is, the most common cause of swollen lymph nodes. Let's look at a cut section of a lymph node to see what happens. Afferent means towards. Afferent lymph vessels bring unfiltered fluids from the body into the lymph node where they are filtered. Efferent vessels, meaning away from, carry the clean fluid away and back to the bloodstream where it helps form plasma. When the body is invaded by foreign organisms, the swelling sometimes felt in the neck, armpits, groin, or tonsils comes from the microorganisms trapped inside the lymph nodes. Eventually, these organisms are destroyed and eliminated by cells that line the node walls. Then the swelling and pain subside.

The lymphatic system filters fluid from around cells. It is an important part of the immune system. When people refer to swollen glands in the neck, they are usually referring to swollen lymph nodes. Common areas where lymph nodes can be easily felt, especially if they are enlarged, are the groin, armpits (axilla), above the clavicle (supraclavicular), in the neck (cervical), and the back of the head just above hairline (occipital).

Swollen lymph nodes, sore throat, fatigue and headache are some of the symptoms of mononucleosis, which is caused by the Epstein-Barr virus. It is generally self-limiting and most patients can recover in 4 to 6 weeks without medicines.

The lymphatic system is a complex system of fluid drainage and transport, and immune response and disease resistance. Fluid that is forced out of the bloodstream during normal circulation is filtered through lymph nodes to remove bacteria, abnormal cells and other matter. This fluid is then transported back into the bloodstream via the lymph vessels. Lymph only moves in one direction, toward the heart.

Lymph nodes produce immune cells to help fight infection. They also filter the lymph fluid and remove foreign material, such as bacteria and cancer cells. They can become swollen from inflammatory conditions, an abscess, cancer, and most commonly from infection. Common areas where lymph nodes can be felt include the groin, armpit, behind the ears, back of the head, sides of the neck and under the jaw and chin.

Lymph nodes play an important part in the body's defense against infection. Swelling might occur even if the infection is trivial or not apparent. Swelling of lymph nodes generally results from localized or systemic infection, abscess formation, or malignancy.