Edema is defined as palpable swelling resulting from fluid accumulation in intercellular tissues, which is caused by abnormal expansion of the interstitial fluid volume.
- The fluid between the interstitium and the intravascular space is regulated by the capillary hydrostatic pressure gradient and the osmotic pressure gradient across the capillaries.
- Fluid accumulation occurs when local or systemic conditions disrupt this balance causing capillary hydrostatic pressure to increase plasma volume and decrease plasma osmolality (hypoalbuminemia), increase capillary permeability or lymphatic obstruction. [1][2]
The rapid progression of generalized pitting edema associated with systemic disease requires prompt diagnosis and management. [1]
Assessment of Oedema
History - Should include:
- Edema time – since when? Acute swelling of the extremity in less than 72 hours is more characterized by deep vein thrombosis (DVT) cellulitis ruptured popliteal cyst acute compartment syndrome due to trauma or recent initiation of calcium channel blockers. chronic accumulation More commonly edema is due to the onset or worsening of chronic systemic diseases such as congestive heart failure (CHF), kidney disease or liver disease.
- Changes of edema with position
- Unilateral or bilateral edema: Unilateral edema can be caused by DVT venous insufficiency Tumor vein obstruction (eg, iliac vein tumor obstruction) lymphatic obstruction (eg, pelvic tumor or lymphoma) or lymphatic destruction (eg, congenital and secondary tumors) radiation or filariasis). Bilateral or generalized swelling suggests a systemic cause such as CHF (especially right side) pulmonary hypertension, chronic kidney or liver disease (leading to hypoalbuminemia), protein-losing enteropathy, or severe malnutrition.
- Medication history and
- Assessment of systemic diseases.[1]
Physical Examination – In physical examination, pitting, tenderness, skin changes, and temperature are evaluated.[1]
Pockmarks: There are two types of edema-type pitting and non-pitting edema. Pitting edema is described as indentations that remain in the edema area after pressure is applied. The timing and extent of its localization depend on the treatment response. Mainly evaluate the medial malleolus The bony part of the tibia and the dorsum of the foot. Nonpitting edema is seen in lymphedema, myxedema and lipedema. [1]
Tenderness: Pain on palpation in the edematous area is associated with DVT and complex regional pain syndrome type 1 (ie, reflex sympathetic dystrophy). In contrast, lymphedema usually does not cause pain to palpation.
Changes in skin temperature color and texture: Warmth in areas of edema is associated with acute DVT and cellulitis. Red, shiny skin and ulcers are to watch out for. Yellow-brown hemosiderin deposits are seen in venous insufficiency. [1]

Methods for quantitative assessment of peripheral edema
There are various methods used in studies to assess peripheral edema. [3]
The most common tools for measuring edema are:
- Volume measurement (using a water meter)
- Circumference measurement (with a tape measure).
- Pitting edema assessment (based on depth and duration of indentation).
Water displacement and ankle circumference had shown a high inter-examiner agreement (intraclass correlation coefficient 0.93, 0.96 right; 0.97, 0.97 left).
Displacement (volume measurement)
The volumeter:
- Introduced to medicine by Glisson in 1622
- Using the same principle as the water displacement principle first discovered by the ancient Greek mathematician Archimedes, which states that the amount of water displaced is equal to the volume of the object immersed in the water.
- The clear acrylic rectangular box (13″x5″x9″) has a spout at the top of one of the short sides and is filled with water until water comes out of the spout. When the water level stabilizes, the patient places one foot in the volume meter, Drained water is collected and measured in the dial cylinder. The amount of water displaced in milliliters is equal to the volume of the foot/ankle or hand.
- For ankles, the volume test can be done while sitting or standing, with knees at 90 degrees and feet flat on the bottom of the volume meter. [3]
- For hands, the participant’s hand was slowly placed into the volume meter with the pronated fingers of the forearm adducted and the thumb facing the spout until the pulps of the middle and ring fingers rested on the volume meter’s stop pins. [4]
Advantages – It is the gold standard tool for measuring edema. [5]
Disadvantages – These methods have various disadvantages in the clinical setting.
- Since the water level needs to be stable, the time must be set a few minutes before the test.
- It is difficult to move once filled with water.
- It requires specialized equipments.
- It’s confusing because they require the patient to immerse their hands in water, so it’s not suitable for certain patient populations. [5
2. Circumference measurement (with a tape measure)
Circumferential Method
The circumference method is one of the circumference measurement techniques. For consistent measurements, each upper or lower extremity is marked with semi-permanent markers at specific locations, refer to the condyles [3]
Figure-of-Eight method
It is also one of the perimeter measurement techniques. It is more reliable than the circumference method because it covers a larger area. Compared to a standard tape measure, a tension control tape measure is better for wrapping around the ankle/foot or hand to measure edema. [5][3] The method of Figure 8 is Swelling in the ankles and hands is usually preferred. It has its own specific points for consistency.
A figure of 8 to measure hand swelling
A figure of 8 to measure ankle swelling
3. Pitting edema
Assessment – Firmly press each limb with your thumb for at least 2 seconds
- Over the dorsum of the foot
- Behind the medial malleolus
- Lower calf above the medial malleolus
The pit depth and the time it took for the skin to return to its original appearance (recovery time) were recorded.
Edema was graded by pit depth (visual inspection) and recovery time from grades 0-4. This scale is used to rate the severity as follows:
- Grade 0: No clinical edema
- Grade 1: Slight pitting (2mm depth), no visible deformation, immediate rebound.
- Grade 2: Slightly deep dimples (4mm), no visible deformation, bounces within 15 seconds.
- Grade 3: Significantly deep pit (6 mm), full and swollen lower extremities that take 30 seconds to rebound.
- Grade 4: Very deep dimples (8 mm) with severe lower extremity contortion that takes more than 30 seconds to rebound. [3]
Conclusion
- More reliable methods of displacement and ankle measurements
- Clinical assessment is highly variable due to its subjective nature
Pitting Oedema
- Indentation recovery time (the time it takes for the indentation to refill) helps determine the diagnosis
- Serum albumin concentration is directly related to dent recovery time (hypoalbuminemic edema recovery time <40 seconds)
Focused assessment: Symmetry of swelling, pain and edema with dependent skin findings (hyperpigmented stasis dermatitis, fatty skin, sclerosing atrophic leukoplakia ulcers) and history of venous thromboembolism [9]
REFERENCES
- Trayes KP, Studdiford JS, Pickle S, Tully AS. Edema: diagnosis and management. American family physician. 2013 Jul 15;88(2):102-10.
- Simon EB. Leg edema assessment and management. Medsurg Nursing. 2014 Jan 1;23(1):44-53.
- Brodovicz KG, McNaughton K, Uemura N, Meininger G, Girman CJ, Yale SH. Reliability and feasibility of methods to quantitatively assess peripheral edema. Clinical medicine & research. 2009 Jun 1;7(1-2):21-31. Dewey WS, Hedman TL, Chapman TT, Wolf SE, Holcomb JB. The reliability and concurrent validity of the figure-of-eight method of measuring hand edema in patients with burns. Journal of burn care & research. 2007 Jan 1;28(1):157-62.
- ↑Nadar MS, Taaqi M. Reliability of Occupational Therapy Students Using the Figure-of-eight Technique of Measuring Hand Volume. Hong Kong Journal of Occupational Therapy. 2013 Jun 1;23(1):20-5.
- ↑ Wendy Huddleston. Lower extremity edema assessment (volumetry). Available from:https://www.youtube.com/watch?v=oR4bvb_DLjQ. [Lasted assessed: 10th Oct, 2020]
- University of Derby. Hand Therapy – Figure of 8 Measurement. Available from:https://www.youtube.com/watch?v=V49LQxtA95I. [lasted assessed: 10th Oct,2020]
- GC Ortho. Figure of Eight Ankle Measurement. Available from: https://www.youtube.com/watch?v=g_0hMZEq1iQ. [lasted assessed:10th oct,2020]
- EBPconsul Pitting edema Available from: https://www.ebmconsult.com/articles/pitting-edema-assessment(last accessed 19.10.2020)