What causes lymphoedema?

The lymphatic system normally returns extra fluid from tissues to the bloodstream. When lymph vessels or lymph nodes cannot move that fluid onward, it collects in nearby tissue and causes swelling, heaviness, tightness, or changes in the skin.

After breast or other cancer surgery, lymph nodes may be removed or disturbed. Radiotherapy can also affect lymph vessels and nodes. Lymphoedema may appear soon after treatment or develop later. Infection, injury, reduced movement, or further blockage can make swelling more noticeable. It can affect an arm, leg, breast, chest, abdomen, face, or neck depending on the drainage area involved.

Arrange an assessment if swelling persists, one limb feels heavier, jewellery or clothing becomes tighter, or the skin feels firm. A clinician may compare both sides, examine the skin, and consider other causes of swelling. Management can include movement, skin care, compression chosen by a trained professional, and specialised lymph drainage. Protect the affected skin from cuts and burns, keep it moisturised, and clean any break promptly.

If you have had a mastectomy or radiotherapy, mention any new swelling at follow-up. Do not start tight compression or intensive massage without advice, particularly if the area is painful, red, hot, or suddenly enlarged.

Seek prompt medical advice for rapidly increasing swelling, redness, warmth, tenderness, fever, or fluid leaking from the skin, because these can signal infection. Sudden swelling with chest pain or breathlessness needs urgent assessment. New swelling after cancer treatment also deserves review so that lymphoedema and other conditions can be distinguished.

Ask which lymph drainage area may be affected, whether you need a lymphoedema specialist, which exercises and skin products are suitable, and how to respond if swelling changes during future treatment.