Causes of lower limb swelling

Swelling of the lower limb may have a local, regional or systemic cause.

Ankle swelling develops when interstitial fluid production exceeds lymph drainage for a sustained period. This could be because the microvascular filtration rate is high, lymph flow is low, or both. (1)

Bilateral lower limb swelling is usually due to systemic conditions (e.g. cardiac failure) and unilateral swelling is often due to local trauma, venous disease or lymphatic disease.

Risk factors associated with chronic ankle swelling are age, morbid obesity, heart failure, chair-bound immobility and neurological deficiency. (2)

If lower limb swelling is due to decreased lymphatic drainage, approximately 80% must be non-functional before lymphoedema becomes clinically evident. (3)

Iatrogenic lower limb swelling due to prescribed medication may occur. There may be oedema following the use of medications such as non-steroidal anti-inflammatory drugs, calcium-channel blockers, thiazolidinediones, corticosteroids, gabapentin, pregabalin, levodopa and oral contraceptives containing oestrogen. (4)

References

1. Mortimer PS, Rockson SG. New developments in clinical aspects of lymphatic disease. J Clin Invest. 2014 Mar;124(3):915-21.
2. Quéré I, Palmier S, Noerregaard S, et al. LIMPRINT: estimation of the prevalence of lymphoedema/chronic oedema in acute hospital in in-patients. Lymphat Res Biol. 2019 Apr;17(2):135-40.
3. Slavin SA, Greene AK, Borud LJ. Lymphedema. In: Weinzweig J, ed. Plastic surgery secrets plus. 2nd ed. Philadelphia, PA: Mosby; 2009.
4. Koo LW, Reedy S, Smith JK. Patient history key to diagnosing peripheral oedema. Nurse Pract. 2010 Mar;35(3):44-52.