The lymphatic system is a network of vessels, nodes, and organs that drains excess interstitial fluid from tissues, transports immune cells, and absorbs fats from the gastrointestinal tract. When this system is damaged, obstructed, or congenitally underdeveloped, fluid accumulates in the tissue spaces, producing the persistent swelling known as lymphoedema. Unlike the temporary swelling of an acute injury, lymphoedema is a chronic condition that progressively worsens without appropriate management.
Primary Versus Secondary Lymphoedema
Primary lymphoedema arises from congenital malformation or absence of lymphatic vessels or nodes. It may present at birth, during puberty, or in early adulthood, and affects women more than men. Milroy disease, Meige disease, and lymphoedema-distichiasis syndrome are named forms with identified genetic causes. Secondary lymphoedema results from damage to a previously normal lymphatic system. In high-income countries, cancer treatment is the most common cause, particularly surgery and radiotherapy that remove or damage lymph nodes. Breast cancer treatment is the single most frequent antecedent. In low-income countries, filariasis, a parasitic infection transmitted by mosquitoes that obstructs lymphatic vessels, causes the majority of secondary cases and affects an estimated 120 million people globally.
Symptoms and Presentation
The hallmark symptom is persistent swelling, typically affecting one or more limbs, though trunk, genital, head, and neck lymphoedema occur in specific clinical contexts. Early lymphoedema may present as a feeling of heaviness or tightness in the limb before visible swelling is apparent. As the condition develops, pitting oedema becomes detectable: pressing a finger into the swollen area leaves a temporary indentation. The skin becomes tight, and clothes or jewellery feel restrictive. Aching, reduced range of motion, and recurrent skin infections known as cellulitis are common. Unlike lipoedema, lymphoedema involves the foot and toes.
The Stemmer Sign
The Stemmer sign is a clinical test used to help confirm lymphoedema. The examiner attempts to pinch and lift a fold of skin on the dorsum of the second toe or finger. A positive Stemmer sign, where the skin cannot be lifted into a fold because it is too thickened and indurated, indicates fibrotic change in the dermis consistent with lymphoedema. It is not present in all cases, particularly in early-stage disease, but a positive result has high specificity for lymphoedema and is a useful clinical discriminator.
Staging
The International Society of Lymphology staging system ranges from stage 0 to stage III. Stage 0 is subclinical: the lymphatic transport is impaired but swelling has not yet appeared. Stage I is early-stage reversible oedema that reduces with limb elevation. Stage II is irreversible swelling that does not fully resolve with elevation and involves fibrotic tissue changes. Stage III describes elephantiasis, the most severe form, with gross swelling, skin changes, and frequent infection.
Why Early Treatment Changes Outcomes
Lymphoedema at stage 0 or I is far more manageable than at stage II or III. The fibrotic tissue changes that develop in advanced disease are not reversible with conservative treatment. Early intervention with compression therapy and manual lymphatic drainage maintains the limb in a reduced and manageable state before fibrosis becomes the dominant pathological process. Patients who begin treatment within the first twelve months of onset consistently achieve better long-term volume control than those who begin treatment later.