The swollen ‘glands’ that you feel – most commonly on your neck when you have a throat infection – are called lymph glands or lymph nodes. They are connected by a complicated network of tubes called lymph channels, which run all over your body. The channels and glands are full of a fluid called lymph, which in turn contains millions of white blood cells. These cells form the basis of your immune system, which helps you to fight off disease.
If your body detects an invader – an infection or another foreign object that it doesn’t recognise – it will mobilise this army of white blood cells. These rush to the spot they’re needed, congregating in the lymph glands closest to where they are needed. Think of your lymph channels as train tracks, the lymph glands as the stations or depots and your white cells as passengers (armed to the teeth to fend off enemies!)
Why do they swell?
Lymph glands are normally about the size of peas. If you’re slim, you may be able to feel even some normal sized glands under your skin. If they fill with white blood cells, they swell and usually become tender. Once the infection has gone they almost always shrink back down to their normal size, although this may take a week or two
Where are they?
Lymph glands are often found in groups or chains in one part of your body. Some of them lie deep inside you, and you can’t feel them even if they’re swollen. Others lie just under the skin.
The main collections of lymph nodes are:
- All around your head and neck. You have groups of lymph nodes behind and in front of your ears; running round the base of your scalp; under your chin and above your collar bone
- In your armpits
- In your groins
Why do they swell?
By far the most common reason for swollen glands is infection. This usually causes swelling the glands nearest the infection. Your network of connecting lymph channels drains the whole of one part of your body. For instance, the lymph glands in your groin are the depot for all the tracks (lymph channels) in your leg, so an infection between your toes can cause swollen glands in your groin on that side. Throat infections, like tonsillitis, will cause the glands in your neck to swell. Some infections, such as glandular fever, cause all the glands in your body to swell, so you may feel glands in your armpits, groins and neck.
Much less commonly, swollen glands can be caused by cancer. Cancer affecting the blood system (leukaemia) or the lymph system itself (lymphoma) will tend to cause glands in more than one area to swell. On the whole, these lymph nodes aren’t tender, at least at first, and tend to grow in size more slowly than those connected with infection.
If cancer in one part of the body spreads through the lymph system, it can cause swelling of the lymph glands nearby. For instance, breast cancer can cause swollen glands in one armpit, and throat or lung cancer can enlarge the glands in the neck.
Should I worry?
Usually not at all! Having swollen glands is often a sign that your body is already working hard to fight off an infection. However, you should get them checked out it:
- You have swollen glands and you aren’t aware of any infection which could be to blame
- Your glands don’t go back to normal within a couple of weeks of any infection settling
- You have other symptoms such as feeling unduly tired, weight loss, night sweats or persistent fevers
With thanks to 'My Weekly' magazine where this article was originally published.
Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.