Pitting Edema vs. Lymphedema: How to Tell Them Apart (and Why It Matters)

If you (or your patients) notice swelling in an arm, leg, or elsewhere, the first question is usually what’s causing it? Two common—but very different—culprits are pitting edema and lymphedema. They can look similar at first glance, especially early on, but their causes, clinical clues, and best treatments diverge. Getting the distinction right prevents delays in care, unnecessary tests, and the wrong therapies.

This guide breaks down the differences clearly, shows how clinicians tell them apart, and offers practical next steps—including when to seek urgent care and how to find a certified lymphedema therapist.

What is Pitting Edema?

Pitting edema is swelling caused by excess fluid in the tissues. When you press a thumb into the swollen area for a few seconds and let go, it leaves a temporary “pit” (indentation) that slowly rebounds. Pitting edema is a sign, not a diagnosis, and usually comes from an underlying systemic or venous issue—think heart failure, kidney or liver disease, medication effects (e.g., some calcium channel blockers), pregnancy, or chronic venous insufficiency. Treating the underlying cause is the main goal. 

Clinicians sometimes “grade” pitting from 1+ to 4+ based on depth and how long the indentation lasts. The classic scale—useful for documentation—has limited reliability, so it shouldn’t be the only thing driving decisions. 

What is Lymphedema?

Lymphedema is chronic swelling caused by impaired lymphatic drainage. It can be:

• Primary present from birth because of congenital or genetic defects in the lymph vessels.
• Secondary (more common) after cancer treatment, lymph node surgery, radiation, infection, trauma, or longstanding venous disease (phlebolymphedema). 

Early lymphedema may pit (because fluid is still relatively mobile), but as protein-rich lymph stagnates, tissues become fibrotic, the swelling turns non-pitting, and skin changes—thickening, hyperkeratosis, papillomatosis—can appear. Lymphedema also increases the risk of cellulitis. A classic exam clue is the Stemmer sign: the inability to pinch a fold of skin at the base of the second toe or finger. A positive Stemmer sign is quite sensitive (~92%) for lymphedema (though not perfectly specific). 

Quick Visual: Pitting Edema vs. Lymphedema

Sources support the exam distinctions and the limits of pitting grades; Stemmer sign sensitivity; and nonsystemic edema/lymphedema nonresponse to diuretics. 

How Clinicians Tell Them Apart

1) History and Pattern

• Time course & laterality: Acute unilateral swelling triggers evaluation for DVT, infection, trauma; chronic bilateral swelling suggests systemic causes (CHF, renal, hepatic) or venous disease. Prior cancer surgery or radiation raises suspicion for secondary lymphedema. 

2) Physical Exam

• Pitting vs. non-pitting: Pitting suggests venous disease, systemic edema, or early lymphedema; non-pitting suggests later-stage lymphedema or pretibial myxedema. 
• Stemmer sign: Positive = strong clue for lymphedema (sensitivity ~92%); a negative sign does not exclude it—especially early or if swelling spares the digits. 
• Skin clues: CVI often shows hyperpigmentation, stasis dermatitis, medial ankle ulcers; lymphedema tends toward thickened/“warty” skin in later stages. 

3) Testing (When Needed)

• Rule out DVT with compression ultrasound if risk is intermediate/high (Wells criteria). 
• Duplex ultrasound with reflux helps confirm chronic venous insufficiency. 
• Lymphoscintigraphy is considered the imaging test of choice for confirming lymphedema (though not always available). Indocyanine green (ICG) lymphography and MRI lymphangiography are adjuncts at specialized centers. 
• Bioimpedance spectroscopy (BIS) can detect subclinical lymphedema (e.g., in breast-cancer survivors) and is increasingly used for surveillance; recent guidance supports lower L-Dex thresholds to flag early change. 

Treatment Paths Diverge

Managing Pitting Edema

Because pitting edema is a symptom, treatment targets the cause:

• Heart failure: diuretics, guideline-directed therapy.
• Medication-induced edema: adjust or switch the culprit drug.
• Venous disease: compression therapy (stockings, adjustable wraps), leg elevation, calf-muscle pump exercises.
• Lifestyle: sodium reduction, activity, elevation when sitting. 

Note: Before prescribing significant compression in lower limbs, clinicians often check an ankle-brachial index to avoid worsening unrecognized arterial disease. 

Managing Lymphedema

There’s no “cure,” but excellent control is possible. The gold-standard is Complete Decongestive Therapy (CDT):

1. Manual Lymph Drainage (MLD)
2. Compression (multi-layer short-stretch bandaging, then fitted garments or adjustable wraps)
3. Decongestive/Remedial Exercises
4. Meticulous skin care

These are supported by international consensus and widely used in practice. Intermittent pneumatic compression, self-care education, and weight management may also help. Diuretics are generally not effective for nonsystemic edema like lymphedema and can be counterproductive if relied upon in place of CDT. 

Some centers also use BIS to catch changes early and intervene before visible progression. Surgical options (e.g., lymphaticovenous anastomosis or vascularized lymph node transfer) are considered in selected patients alongside ongoing conservative care. 

Swelling can signal emergencies. Get prompt medical evaluation for any of the following:

FAQs

Find a Certified Lymphedema Therapist

Hands-on care and garment selection are where outcomes really improve. The Norton School Therapist Referrals page can help you locate a Certified Lymphedema Therapist (CLT) near you. You can also learn what a CLT does and how to vet credentials in our guide. 

More helpful reads from our blog:

• Finding a Lymphedema Therapist Near You (step-by-step walkthrough of our referral tool). 

• Stemmer’s Sign and its Crucial Connection to Lymphedema (what the sign is and how it’s used). 

Key Takeaways

• Pitting edema = a sign that often points to systemic or venous causes; treat the cause, and use compression appropriately.
• Lymphedema = a chronic lymphatic condition; may pit early but often non-pitting later, with positive Stemmer sign and characteristic skin changes; best treated with CDT and compression, not diuretics.
• When in doubt, especially with acute unilateral swelling or systemic symptoms, seek urgent evaluation. 

References & Further Reading

1. American Academy of Family Physicians. Peripheral Edema: Evaluation and Management in Primary Care. (Nov 2022). Practical algorithms for differentiating causes; notes limits of pitting scale; outlines testing and management principles. 
2. Mayo Clinic. Edema—Symptoms and Causes. Accessible overview of systemic causes and general care. 
3. Cleveland Clinic. Lymphedema: Symptoms, Causes & Treatment. Patient-friendly overview of lymphedema. 
4. International Society of Lymphology (ISL). 2020 Consensus Document: Diagnosis & Treatment of Peripheral Lymphedema. Core reference for CDT and clinical practice. 
5. Goss JA, Greene AK. Sensitivity and Specificity of the Stemmer Sign for Lymphedema. Reports ~92% sensitivity for lymphedema; helpful but not perfectly specific. 
6. Villa G, et al. Procedural Recommendations for Lymphoscintigraphy in Lymphedema. Imaging best practices; supports lymphoscintigraphy as the test of choice in many cases. 
7. BIS in Lymphedema Surveillance. Updated guidance supporting lower L-Dex thresholds to detect subclinical change sooner. 

This article is for education only and is not a substitute for medical advice. If you have new or worsening swelling—especially with pain, redness, breathing issues, or fever—seek care promptly.