Lymph is a colourless fluid similar in composition to intercellular fluid(tissue fluid). As part of the continual processes of circulation, some of the tissue fluid is absorbed into the bloodstream via the capillaries, and the remainder, containing the greater part of the proteins found in tissue fluid, is absorbed into the smallest lymphatic vessels. These form part of a system which parallels the blood circulation, but with the important difference that it has no central pump (i.e., the heart) to help it circulate. Instead, the movement of lymph depends on pressure from the normal activity of the surrounding muscles. A sedentary lifestyle may, therefore, lead to inefficient circulation of lymph.

Lymph is involved in the absorption of fats from the intestines, in the drainage and removal of toxic wastes from all parts of the body, and in the body's response to infection. (This is discussed elsewhere, under the heading of IMMUNE SYSTEM.)

The other main function of the lymphatic system is the drainage of fluids and poor circulation of lymph may lead to oedema, that is, localised or general retention of fluid. This can be seen in people whose work involves long periods of standing, and who may have swollen ankles at the end of the working day. Cellulite, involving the retention of toxic waste and fluids, particularly in the region of the thighs, hips and buttocks, is also related to sluggish lymph function.

Specialised forms of massage are very effective in reducing swelling and encouraging a more efficient drainage of lymph, especially when combined with such essential oils as Fennel, Geranium, Juniper and Rosemary. When treatment is continued over a long period, Black Pepper can be used in place of Rosemary and some therapists include Patchouli. The massage is directed from the extremities towards the area of the clavicle (collarbone) where the lymph drains into the subclavian veins. There are several different systems of lymph massage, but the majority of aromatherapists are trained in one or other of them. Because this form of massage increases the amount of lymph entering the bloodstream, the amount of water extracted from the blood as it passes through the kidneys will also be raised. Consequently, an increase in urination will be experienced after lymph drainage massage, and this is heightened by the fact that several of the oils used with this massage are also diuretic.

The benefits of such massage will be greatly increased by bathing with a selection of the same oils, and by gentle exercise and skin brushing. This is done with a dry brush, and follows the same direction as the massage strokes (from the extremities towards the collarbone). A cleansing diet may also be necessary.

In rare cases, fluid retention will not respond to lymphatic drainage massage, or re-occurs very quickly after treatment, and medical help must be obtained urgently, as this could indicate serious kidney disease or even heart failure. However, people who are so seriously ill are not likely to be consulting an aromatherapist without the knowledge and consent of their doctor.

Pre-menstrual fluid retention can be greatly reduced by lymphatic massage carried out one or two days before swelling is usually experienced.

Apart from such easily visible disorders as oedema and cellulite, a less-than-efficient lymph system can contribute to many conditions where poor elimination of toxins is involved. Catarrh is a typical example, also some skin disorders, headaches, migraine etc.

People who have very poor resistance to infection, can also benefit from regular lymphatic massage, and it may be of help during convalescence. This is related to the role played by lymphoid tissue in fighting infection and is more fully described elsewhere in this book.

A very important contraindication for lymphatic massage is cancer. The lymphatic system is a route by which malignant cells can move from one part of the body to another (metastasis) and give rise to secondary cancers, and treatments involving this system are generally advised against.

See also entries for CELLULITIS, PMT and especially for IMMUNE SYSTEM, which discuss the other functions of the lymphatic system.