What Is Pitting Edema?

Pitting edema occurs because of a buildup of fluids that causes swelling, usually in the lower body. Edema is called "pitting" when there's enough swelling to cause a “pit" when pressing on the affected area. Non-pitting edema doesn’t leave a mark and is usually caused by fluids with relatively higher protein and salt content.

The severity of pitting edema is clinically assessed on a scale, based on how deep the pit is and how long it takes to go away. Treatment for edema involves addressing the underlying factors causing the issue, based on the diagnosis and assessment of pitting edema.  

This article explains the underlying causes of pitting edema, as well as its symptoms. It presents lifestyle changes and other interventions used to treat pitting edema.

Symptoms

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

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

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 with varying degrees of severity.

For example, some cases are due to gravity when you stand for long periods and will stop when you change position. Lifestyle factors, like high salt intake, can lead to fluid retention and can be modified through diet. Other causes, though, include serious illness, such as chronic obstructive pulmonary disease (COPD).

Medication

Pitting edema can be a side effect of several types of medications and can also be a sign of an allergic reaction. These medications include:

• Corticosteroids (prednisone, prednisolone, triamcinolone, and others)
• Nonsteroidal anti-inflammatory drugs (aspirin, ibuprofen, naproxen)
• Heart disease drugs (acebutolol, betaxolol, bisoprolol)
• High blood pressure medications (diuretics, beta-blockers, ACE inhibitors)
• Certain diabetes medications (thiazolidinediones)

Deep Vein Thrombosis

Deep vein thrombosis (DVT, a clotting of veins deep in the body) typically affects older adults but it can be seen in young people, including children. The clotting, usually located in the calf of the lower leg, can cause edema and pain, and it requires immediate treatment with anticoagulants or other medication.

While DVTs can be treated, they also can lead to complications such as post-thrombotic syndrome (PTS). People with PTS also may experience edema at the affected site, which may call for the use of elastic compression stockings and other longer-term interventions.

Weakening in the walls of veins in the legs (venous insufficiency) also leads to swelling in the lower limbs or elsewhere. This leads to the formation of varicose veins.

Congestive Heart Failure

Congestive heart failure (CHF) occurs when the heart muscle is no longer able to pump well enough to meet the body's need for oxygen in the blood. It can be caused by left-sided or right-sided failure, based on which of the heart's four chambers are involved. Or, both sides may fail in CHF.

It's usually right-sided failure that leads to an accumulation of fluid in the lower legs (peripheral edema) or lower back (sacral edema). The edema also can affect the lungs. Treatment is focused on the underlying cause of the CHF, which is usually a heart condition but may be related to infection, cancer treatment, or another cause.

Kidney Disease

Kidney diseases (nephrotic syndrome, acute glomerulonephritis) can lead to edema because the body's ability to remove fluids through urination is compromised. The swelling can affect the hands, feet, and ankles, but also may appear in the face.

Over time, kidney disease also affects other body systems and causes complications such as high levels of electrolytes, the key minerals that include potassium and calcium. With renal hypertension, the pulmonary edema can affect the lungs.

Cirrhosis

Liver cirrhosis is a severe scarring of liver tissue that causes fibrosis and typically leads to a progressive loss of liver function. Symptoms in the later stages of the disease include edema in the feet, ankles, and legs due to a buildup of fluid. Often, fluid will build up in the abdomen, too.

Hepatitis of the liver can lead to edema. Hepatitis related to alcohol use also can lead to swelling in the body due to a condition called portal hypertension, which stops blood from returning to the liver from the digestive system.

Pregnancy

Pregnancy and related hormonal changes can lead to edema because they cause fluid retention. Pregnant people also have more blood volume in their bodies. It's quite common but if you experience sudden swelling, get it checked out. It may be a sign of preeclampsia, a serious condition that needs medical attention right away.

Hormonal changes due to menstruation also can cause swelling in the feet, ankles, and other parts of your lower limbs.

Hot Weather

Heat edema is not uncommon, and is a mild form of heat-related illness. These illnesses also include muscle cramps, heat exhaustion, and potentially fatal heat stroke.

The swelling of the extremities, sometimes with facial flushing, usually resolves once a person is removed from the heat and kept with their legs resting up to help the swelling go down.

Risk Factors

People with certain underlying medical conditions, like obesity, are at a higher risk of edema, even if the edema is caused by an environmental factor like heat or a temporary condition like pregnancy.

Lifestyle factors also can contribute to the development of edema. They include:

• Smoking, which can lead to vascular damage in the lower extremities
• Diets high in sodium (salt) intake
• The use of certain medications

Alcohol use disorders that lead to cirrhosis and other conditions also may lead to pitting edema.

Grading Scale and Diagnosis

Accurate diagnosis and assessment is essential for proper treatment of pitting edema. The pitting edema scale, used to assess the grade 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.

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 EKGs) 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 pitting 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, pitting 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.

Summary

Pitting edema is a type of swelling, often in the lower extremities, that causes enough fluid retention to leave a pit (or indentation) when you press on the affected area. How serious the edema is will depend on how deep the pitting is and how long it takes for it to disappear on your skin after pressing. The pitting edema scale is used to measure it.

A wide variety of conditions can cause pitting edema and some of them, like congestive heart failure can be serious. It’s essential to see a healthcare provider if you think 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.

Treatment will vary based on the underlying cause of the edema, so it's important to get an accurate diagnosis as early as possible. Your healthcare provider can then discuss the prognosis, or possible outcomes, for your condition.