Swollen lymph nodes are a common and often difficult-to-pin-down symptom of a wide variety of different illnesses and medical conditions. Although they are quite common, they can also sometimes be indicators of a very serious condition requiring medical attention. For this reason, it is important to know when to be concerned about a lymph node - and, equally, when not to be.
The reason swollen lymph nodes are common relates to their function. There are about five hundred of these small, spherical organs scattered throughout the human body, including easily noticeable sets of lymph nodes under the armpit, in the neck, and in the groin and inner thigh area. Each of these serves as a reservoir for white blood cells in the body's immune system. When an infection or other foreign incursion into the body occurs, nearby lymph nodes tend to swell up and become palpable (i.e. you can feel them) as they resist the infection. Normally, the infection will pass and the lymph nodes will shrink back to their normal size again.
Assessing whether to be concerned about a swollen lymph node involves three factors: size, persistence, and how the lymph node feels. Normally, a lymph node should be less than a half-inch in diameter, roughly like a pea or a bean. You should call your doctor and seek medical advice if the lymph node has swelled to more than an inch long or wide, if it hurts to the touch, or if it causes pain or difficulty when moving a nearby joint (such as lymph nodes in the armpit causing pain when you move your arm). You should also call your doctor if you can feel swollen lymph nodes in multiple locations around the body, or if swollen lymph nodes persist for more than a month without beginning to shrink again. You should also see a doctor if the swollen lymph node feels extremely hard or cannot be moved apart from the surrounding body tissue; either of these is a risk factor indicating a possible tumour.
In addition, several circumstances indicate a potential emergency. If you have swollen lymph nodes in the neck which are causing difficulty swallowing or breathing, for example, these need to be taken care of immediately. There is also reason for concern if the swollen lymph node increases rapidly over time (for example, noticeable changes over a period of just a few hours), or if a red skin patch or rash is visible over top of the lymph node.
Even in these cases, you should remember that in almost all cases swollen lymph nodes are not necessarily indicators of serious illness - any manner of causes can result in swollen lymph nodes, including the common cold. However, they can also be signs of much more serious conditions, including cancer (cancer of the lymph nodes is known as lymphoma). For this reason it is important to check on any troublesome lymph nodes early, especially if you cannot think of a recent infection or illness which might explain the swollen lymph nodes. Only a doctor can determine for certain whether or not you need to be concerned about a lymph node.
- Sources and Further Reading -
FamilyDoctor.org. "Neck Swelling."
Mayo Clinic. "Swollen Lymph Nodes."
Seattle Children's Hospital. "Seattle Children's Hospital."