The breasts and lymphatic system

• A quick guide to what's on this page
• The breasts
• Breast size and density
• Lymph glands and the lymphatic system
• Other sources of information

The breasts are made up of

• Fat
• Connective tissue
• Gland tissue divided into lobes

A network of ducts spreads from the lobes towards the nipple. If you have ductal carcinoma in situ (DCIS), cancer cells have been found inside these ducts.

The breasts are not usually the same size as each other. They may also feel different at different times of the month - just before a period they can feel lumpy.

You may have heard or read about 'breast density'. This changes with age. Younger women have more glandular tissue in their breasts, which makes them dense. Once a woman is past her menopause, the glandular tissue is gradually replaced by fat, which is less dense. During breast screening it is harder to read a mammogram if the breast tissue is dense. So mammograms are not as reliable for young women. Specialists have also found that older women who take hormone replacement therapy (HRT) have denser breasts than would be expected for their age. This is related to the HRT. It isn't a problem in itself, but it may make mammograms less accurate for these women.

Get to know your breasts over time. Learn what natural changes take place during your periods and at other times. Look at your breasts when you change your clothes. Or feel your breasts - for instance when you take a bath. Look for changes that seem unusual for you. If you find an unusual change, see your doctor as soon as you can.

A 'tail' of breast tissue, under the skin, leads into the armpit (axilla). The armpits have many lymph glands, also known as lymph nodes. The diagram above shows the network of lymph glands around the breast. They are part of the body's lymphatic system. There is also a chain of lymph nodes that runs up the centre of your chest, by your breast bone. This is called the 'internal mammary chain'.

The lymphatic system is made up of a network of lymph glands, connected throughout the body by tiny tubes (vessels) called lymph vessels. Lymph glands are part of the natural drainage system of the body. Lymph is a yellow fluid that flows through the lymphatic system and eventually drains into veins. This system helps to get rid of waste products from the body.

Tissue fluid bathes the body's cells, drains into the lymphatic system and is recirculated. Lymph glands are important in cancer care because any cancer cells that have broken away from a tumour can be carried by this tissue fluid to the nearest lymph glands. This is why doctors always examine the lymph glands. If you have cancer, but no cancer cells in any of your lymph glands, your cancer is less likely to have spread.

There are many books and booklets about breast cancer, some of which are free. Look at our breast cancer reading list.

Contact other organisations - you can find details in the list of breast cancer organisations and websites. Many have information and free leaflets about the breasts and how to care for them. Breast Cancer Care has a leaflet about breast awareness called 'Taking good care'. You can ask them to send it to you.