Pitting Edema Grading: When Swelling Becomes Serious

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Edema is a buildup of fluids that causes swelling, usually in the lower body. When this swelling is such that you can leave an indentation, or “pit,” by pressing on it, it’s called pitting edema. This is in contrast to non-pitting edema, which doesn’t leave a mark and is usually caused by the accumulation of fluid with relatively higher protein and salt content.

Pitting edema, like its non-pitting counterpart, arises as swelling, usually in the legs, ankles, or feet (though it can occur in the hands). The severity of this condition is clinically assessed on a scale based on how long it takes the indentation to disappear. Since treatment involves addressing the underlying factors causing the issue, this scale is critical for the diagnosis and assessment of pitting edema.   

Common Causes of Pitting Edema

Verywell / Zoe Hansen

Related Symptoms

The symptoms of pitting edema arise due to fluid and blood buildup, ranging in severity depending on what’s causing the issue. They can be localized (confined to a specific area) or generalized (present throughout the body). Generally, symptoms include:

  • Swelling, usually in the legs, feet, or ankles
  • Pressing on affected areas leaves an indentation that gradually fills in
  • Pain and tenderness
  • Warmth, discoloration, and changes in the texture of affected areas

Pitting Edema Complications

If untreated, pitting edema can lead to cracking, peeling skin, while raising the risk of infection.

Causes

Whereas non-pitting edema typically develops due to disorders of the lymph nodes (lymphedema) or thyroid (myxedema), pitting edema is seen in a broader range of cases. Varying in seriousness, the most common causes include:

  • Gravity: Standing or walking for long periods of time causes fluid to collect in the feet and legs. This can be compounded by obesity, a risk factor for the condition.
  • Circulation problems: Weakening in the walls of veins in the legs (venous insufficiency) also leads to swelling in the lower limbs or elsewhere. This also leads to the formation of varicose veins.
  • Dietary factors: High salt intake in the diet can lead to fluid retention, as can insufficient protein, malnutrition, and malabsorption (the inability of the digestive system to get enough nutrients).  
  • Hormonal factors: Pregnancy and menstruation are also common causes of fluid retention and swelling in the lower limbs.
  • Injury: Localized edema is seen due to injury, burns, or as the result of surgery. Infections can also cause localized swelling.

Medications

In addition, pitting edema is a side effect of several types of medications and can also be a sign of an allergic reaction. These medications include:

Severe Causes

Pitting edema is also associated with several much more serious, and sometimes fatal, conditions:

Grading Scale and Diagnosis

Accurate diagnosis and assessment is essential for proper treatment of pitting edema. Edema grading, which assesses the scale and scope of the swelling, is central to this process. Doctors categorize cases into four grades, from 1+, the least severe, to 4+, the most severe.

In this examination, the doctor presses on an affected area—usually the top of the foot, outer ankle, or lower calf—for two seconds. The severity of the case is based on the size of the remaining impression, and the amount of time it takes to “rebound,” or disappear.

The Edema Grading Scale
 Grade Characteristics
1+ Trace Pitting/impression of 2 millimeters (mm) or less, rebounding immediately. No visible deformity.
2+ Mild Swelling with no visible deformity. The pit is between 2 mm and 4 mm and takes up to 15 seconds to rebound.
3+ Moderate A noticeably deeper pit of 4 mm to 6 mm that lasts as long as 30 seconds. Swelling is more intense in the surrounding extremity.
4+ Severe A pit of 6 mm to 8 mm in depth that takes more than 30 seconds to disappear, accompanied by visible deformity and swelling in the area.
A quick breakdown of edema grades and their characteristics.

In addition to grading, doctors will also perform exams and tests to isolate what’s causing the pitting edema. Specific tests vary based on the suspected underlying cause and can include:  

  • Physical examination: Alongside grading, this involves checking pulse, heart rate, and other vitals. Medical history and medications are also assessed.
  • Blood tests: Doctors test albumin levels in the blood, a protein derived in the liver, as these are directly related to edema and can signal liver or kidney problems.
  • Urinalysis: Chemical and microscopic analysis of urine is performed to assess kidney and liver health.
  • Cardiac testing: Echocardiograms (also known as ECGs or EKs) or echocardiographs, among other tests, are used to assess the heart’s electrical patterns to evaluate cardiac health.
  • Imaging: X-ray or other forms of imaging may be used to assess any clots or blockages of veins thought to be causing the swelling.

Treatment

Treatment depends on the severity of the pitted edema as well as whether or not the patient has any other underlying causes. The type of therapy and medical intervention can be closely tied to the grade of the case, and it can vary a great deal. Common approaches include:

  • Leg elevation: Keeping affected feet or legs elevated can help resolve milder cases of edema.
  • Support garments: Wearing special compression stockings may be recommended to improve blood circulation in the legs.
  • Dietary interventions: Cutting salt intake and stopping alcohol consumption, among other interventions, may be recommended.
  • Medications: If medications are causing the edema, your doctor may tell you to stop taking them. In some cases, diuretics (water pills) are prescribed to get rid of excess fluid buildup.

Additionally, pitted edema resolves when the liver, kidney, or heart problems causing it have resolved. As such, surgery, other medications, and lifestyle changes, among other therapies, may be employed as well.

A Word From Verywell

Since such a wide variety of conditions can cause pitted edema—and since some of them can be very dangerous—it’s essential to get help if you suspect you’re experiencing it. The presence of any kind of swelling is a cause for concern, especially if it’s related to a more serious health issue.

Be open with your caregiver and receptive to how you’re feeling. The more you’re able to tell your doctor about your symptoms, lifestyle, and health status, the better off you’ll be.   

Frequently Asked Questions

  • What is the correct way to grade edema?

    Edema is graded by pressing the thumb into an affected area—usually the top of the foot, the outer ankle, or the lower calf—for two seconds. The grade is determined by measuring the size of the indentation (or “pit”) as well as the amount of time it takes for it to disappear (or “rebound”).

  • When edema falls between two grades, do you use the higher or lower grade?

    Since each grade of edema is defined as a range, rather than a single point, scores can’t fall between grades. For instance, grade 4 edema, the most severe type, is defined as having a pit anywhere over 6 mm in depth, taking over 30 seconds to rebound.


    Though relatively reliable, edema grading is imperfect. Ultimately, the choice of whether to treat a borderline case as being of more or less severity depends on other factors.  

  • How do I describe edema during my physical?

    When seeing your doctor about your edema, you’ll want to be able to provide helpful information about your case. During your appointment, you’ll need to talk about:

    • The size and location of swollen areas
    • The presence of any pain or discomfort
    • The appearance of affected area
    • What your diet looks like, especially the amount of salt intake
    • Any other health conditions you have or health history
    • What medications you’re taking


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4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Zahir S. Edema: pitting vs. non-pitting. Updated August 19, 2015.

  2. Physiopedia contributors. Edema assessment. Updated October 19, 2020.

  3. Cleveland Clinic. Edema: causes, symptoms & treatment. Updated October 22, 2018.

  4. National Institutes of Health. Swelling. Updated October 10, 2020.