Can radiotherapy cause lymphoedema?

The resulting swelling can develop in a nearby arm, leg, breast, chest, genitals, face, or neck, depending on the treated area. It may appear during treatment or later.

The lymphatic system returns tissue fluid to the bloodstream. Radiotherapy can cause inflammation and later scarring in treated tissues, which may slow lymph flow. Surgery that removes or disrupts lymph nodes can add to this effect when both treatments involve the same region.

Early changes can include heaviness, tightness, aching, puffiness, reduced flexibility, or clothing and jewellery feeling tighter. Swelling is not automatically lymphoedema: infection, a blood clot, cancer-related obstruction, and other conditions can look similar and require different care.

Contact your treatment team when swelling, heaviness, or tightness first appears. Early assessment can identify the cause and establish a baseline. A lymphoedema specialist may recommend skin care, suitable movement, compression garments, or specialised massage after checking that these measures are appropriate.

Protect the skin from cuts and burns, moisturise dry areas, and treat small injuries promptly. Keep active within the limits given by your team, increasing activity gradually. Avoid buying tight compression products without fitting advice because the pressure and size need to suit the affected area.

Get same-day medical advice if a swollen area becomes red, hot, increasingly painful, or tender, especially with fever, chills, or feeling unwell. These features can indicate a skin and tissue infection that needs prompt treatment.

Sudden swelling in one limb, particularly with chest pain, breathlessness, coughing blood, or faintness, requires urgent assessment because a blood clot must be excluded.

Ask which body area could be affected, what early changes to monitor, whether previous surgery changes your risk, and how to access a trained lymphoedema therapist. Request clear instructions for exercise, compression, travel, and skin problems.