Pitting Edema in Legs: Causes and When to See a Doctor

What is the difference between pitting and non-pitting edema?

When you press on swollen skin and hold for a few seconds, pitting edema leaves a visible dent that slowly fills back in. Non-pitting edema springs back immediately with no indentation.

Non-pitting edema tends to occur with lymphatic problems or hypothyroidism, where the fluid has a thicker, protein-rich composition. Pitting edema is more typical of conditions that increase pressure in the venous system or reduce the proteins that keep fluid in the bloodstream — such as heart failure, kidney disease, or liver disease 1Ref 1Eberhardt RT, Raffetto JD (2014).Chronic Venous Insufficiency.Chronic venous insufficiency as a major cause of bilateral lower-extremity pitting edema; pathophysiology of venous valve incompetence, venous hypertension, and fluid leakage; management with compression therapy.

The distinction helps clinicians narrow the likely cause, though both types need evaluation if they are new, worsening, or accompanied by other symptoms.

What are the most common causes of pitting edema?

Heart failure. When the heart does not pump efficiently, pressure backs up in the veins, and fluid leaks into surrounding tissues — especially in the lower legs when upright and the back when lying flat. This is one of the most clinically important causes of lower-extremity pitting edema 2Ref 2Heidenreich PA, Bozkurt B, Aguilar D, et al. (2022).2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure.Heart failure as a major cause of lower-extremity pitting edema; evidence-based management including diuretics, sodium restriction, and echocardiographic evaluation. Accompanying symptoms often include shortness of breath, fatigue, and reduced exercise tolerance.

Chronic venous insufficiency. When the valves in leg veins do not close properly, blood pools in the lower legs, raising venous pressure and causing fluid to leak into surrounding tissue 1Ref 1Eberhardt RT, Raffetto JD (2014).Chronic Venous Insufficiency.Chronic venous insufficiency as a major cause of bilateral lower-extremity pitting edema; pathophysiology of venous valve incompetence, venous hypertension, and fluid leakage; management with compression therapy. This is among the most common causes of bilateral ankle and calf swelling in adults, particularly those who stand for long periods. Over time, skin changes such as discoloration, thickening, and ulceration can develop in severe cases.

Kidney disease. Damaged kidneys may lose protein in urine (reducing blood proteins that hold fluid in the vessels) or fail to excrete enough salt and water — both of which promote edema.

Liver disease. Low albumin from liver disease reduces the blood's ability to hold fluid in vessels, leading to fluid accumulation.

Medications. Calcium channel blockers (commonly used for blood pressure), some diabetes medications (thiazolidinediones), NSAIDs, and steroids can all cause lower-extremity pitting edema.

Prolonged immobility or dependency. Long flights, extended sitting, or having legs dependent (hanging down) for long periods can cause mild, temporary edema — generally harmless.

Pregnancy. Fluid retention is common in pregnancy, particularly in the third trimester.

Is pitting edema in one leg different from both legs?

One-sided (unilateral) edema is more likely to suggest a local cause — a blood clot in the deep veins (deep vein thrombosis or DVT), a localized infection, or a lymphatic problem 3Ref 3Marcus GM (2020).Evaluation and Management of Premature Ventricular Complexes.Role of leg ultrasound and clinical evaluation in identifying unilateral edema causes including deep vein thrombosis. A DVT can be dangerous because the clot can break off and travel to the lungs (pulmonary embolism). New one-sided leg swelling — especially with pain, warmth, or redness — warrants prompt medical evaluation.

Both-leg (bilateral) edema is more typical of a systemic cause — heart failure, venous insufficiency, medications, kidney disease, or low albumin 1Ref 1Eberhardt RT, Raffetto JD (2014).Chronic Venous Insufficiency.Chronic venous insufficiency as a major cause of bilateral lower-extremity pitting edema; pathophysiology of venous valve incompetence, venous hypertension, and fluid leakage; management with compression therapy2Ref 2Heidenreich PA, Bozkurt B, Aguilar D, et al. (2022).2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure.Heart failure as a major cause of lower-extremity pitting edema; evidence-based management including diuretics, sodium restriction, and echocardiographic evaluation. It is often worse at the end of the day and improves after elevating the legs overnight.

How is pitting edema evaluated?

A clinician will review your symptoms, current medications, and overall health history. The physical exam grades the severity of pitting (typically on a 1+ to 4+ scale). Common investigations include:

• Blood tests to assess kidney function, liver function, albumin, and thyroid
• Urine test to check for protein
• ECG and echocardiogram if heart failure is suspected 2Ref 2Heidenreich PA, Bozkurt B, Aguilar D, et al. (2022).2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure.Heart failure as a major cause of lower-extremity pitting edema; evidence-based management including diuretics, sodium restriction, and echocardiographic evaluation
• Leg ultrasound if a DVT is being considered 3Ref 3Marcus GM (2020).Evaluation and Management of Premature Ventricular Complexes.Role of leg ultrasound and clinical evaluation in identifying unilateral edema causes including deep vein thrombosis

The goal is to identify any treatable underlying cause, not just manage the swelling symptomatically.

What helps reduce pitting edema?

Treatment depends on the cause:

• Heart failure is managed with diuretics (water pills), medications that reduce cardiac strain, and limiting sodium and fluid intake 2Ref 2Heidenreich PA, Bozkurt B, Aguilar D, et al. (2022).2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure.Heart failure as a major cause of lower-extremity pitting edema; evidence-based management including diuretics, sodium restriction, and echocardiographic evaluation.
• Venous insufficiency is managed with compression stockings, leg elevation, and sometimes procedures on the veins 1Ref 1Eberhardt RT, Raffetto JD (2014).Chronic Venous Insufficiency.Chronic venous insufficiency as a major cause of bilateral lower-extremity pitting edema; pathophysiology of venous valve incompetence, venous hypertension, and fluid leakage; management with compression therapy. Graduated compression applying appropriate pressure at the ankle is a cornerstone of conservative treatment.
• Medication-related edema may improve by switching to an alternative medication.
• Mild, positional edema often responds to elevating the legs above heart level for 30 minutes several times a day, wearing graduated compression stockings, and reducing dietary sodium.

A Gale primary care clinician can evaluate new or worsening edema, review your medications, order the appropriate tests, and refer you to a specialist if heart, kidney, or vascular disease is suspected.