There are eleven questions one should ask to a patient who presents with a history of swollen legs. [Longmore et al 2014; Hall 2011a, Hall 2011b, Hall 2011c, Williams et al 2013]. These can be divided into three sets of questions: questions about the edema itself, questions about the extent/complications, and questions about the etiology.
Questions about the edema itself
What is the duration of the edema? If the onset is acute (<72 hours), deep vein thrombosis should be strongly considered [Ely et al, 2005]. The 72-hour cutoff is commonly cited but arbitrary and not well supported with evidence. Deep vein thrombosis should also be considered in patients presenting after 72 hours with otherwise consistent findings.
- Side and site [Longmore et al 2014, Hall, 2011b, McCollum and Chetter, 2013]
Edema is typically dependent (distributed by gravity), which is why legs are affected early. Ask if the edema is localized to the ankles, or if the swelling is extending above to the legs.
Ask which leg is affected, or if both are affected. Bilateral edema implies systemic disease [Longmore et al, 2014] Deep vein thrombosis usually occurs in one lower limb. Bilateral deep vein thrombosis may also occur, however. When the swelling is bilateral, deep vein thrombosis must be differentiated from other causes of systemic edema, such as hypoproteinemia, renal failure, heart failure, and intake of drugs such as vasodilators. Unilateral edema, and swelling that is not dependent, may indicate trauma or a tumor.
The most common presentation of a deep vein thrombosis is pain and swelling, especially in the calf [McCollum and Chetter, 2013]. Deep vein thrombosis and reflex sympathetic dystrophy are usually painful. Chronic venous insufficiency can cause low-grade aching. Lymphedema is usually painless [Ely et al, 2005].
- Alleviating and exacerbating factors
Ask if the edema improves on lying down. Dependent edema improves during the night, because the fluid moves to the new dependent area, causing a sacral padding. For the same reason the edema is worst in the evenings as prolonged standing or walking results in increasing swelling of the legs.[Longmore, 2014] Venous edema is more likely than lymphedema to improve overnight [Ely et al, 2005].
Questions about the extent or the complications of the edema
- Skin changes [Alguire and Mathes 2015]
Ask about skin changes like irritation, redness, itching, oozing of the skin. Ask about breaks in continuity of skin (ulcers).
Pooling of blood in the legs often causes the skin to become irritated and inflamed. This can cause redness, itching, dryness, oozing fluid, scaling, open sores from scratching, and crusting or scabbing. Some people develop an area of intensely painful skin that turns red or brown, and is hard, and scar-like. This usually develops after many years of venous disease but can occur suddenly.
Open, non-healing sores caused by chronic venous disease often begin as small sores but can expand to become quite large, usually painful, tender to touch, shallow, have a red appearance at the bottom, and may ooze or drain small to large amounts of fluid.
Questions about conditions that may have caused the edema
Ask about trauma. Inflammation following trauma is characterised by vasodilation of local blood vessels, increased permeability of the capillaries allowing leaking of large quantities of fluid into the interstitial spaces. [Hall 2011b]
In women of childbearing age, ask about pregnancy. During pregnancy, various hormones can result in development in edema. [Hall 2011c, Alguire and Mathes, 2015]. Pregnancy can be associated with pedal edema, if a patient has pre-eclampsia. Further, pregnancy predisposes to deep venous thrombosis, causing “phlegmasia alba dolens” or, worse, “phlegmasia cerulaea dolens”.
- Periods of immobility
Ask about recent periods of immobility. Immobility is a risk factor of thromboembolism [McCollum and Chetter, 2013].
- Tumours and irradiation
Ask about a history of pelvic/abdominal neoplasm or radiation. These can predispose to venous thrombosis [Ely et al, 2005].
Ask about a history of drug intake [Talley and O’Connor, 2010; Yaqoob 2012]. Estrogen has a weak aldosterone-like effect, and causes a mild salt retention. This is typically associated with a weight gain in pre-menstrual phase. Mineralocorticoids like aldosterone cause sodium retention, and liquorice has aldosterone-like actions. Calcium channel blockers like dihydropyridine (nifedipine) cause an increased capillary pressure due to relaxation of pre-capillary arterioles. This can result in an edema. Prednisone and anti-inflammatory drugs are also common causes of leg edema. [Ely et al, 2005].
- Systems review for heart, liver, kidney, or sleep disorders