Edema – Symptoms, risk factors and treatment options you must know about

Edema is a kind of swelling due to or accumulation of interstitial fluid. Interstitial fluid is a fluid (salt and water) found in the spaces between the cells and it constitutes around 20 percent of the body weight, under normal conditions. [1] This percentage is maintained by fluids leaking from the capillaries into the spaces and subsequent removal of interstitial fluid by the lymphatic system.

edema occurs when this balance is disturbed because of:

• Increase in hydrostatic pressure, which causes the fluid to filter into the interstitial spaces.
• Decrease in oncotic pressure that causes the proteins in the fluid to accumulate in the interstitial spaces. Oncotic pressure is a pressure applied by proteins inside the blood vessel that pull water into the circulatory system.
• Obstruction to lymphatic drainage.

The swelling in edema can be localised, that is, occurring in one particular area of the body, or the swelling can be more general.

Symptoms and signs of edema

• Swelling or puffiness, most commonly found on the lower legs and ankle.
• An indent when pressure is applied and then removed from the affected area.
• Skin discolouration or shiny skin
• Aching limbs

Types of edema

You know it is not just a swelling but an edema when you press lightly on the affected skin with your finger and then remove your finger, the indentation/ dimple remains. This is the classic type of edema due to fluid retention and is known as the pitting type of edema.

Having said that, there is a non-pitting type of edema as well, in which the indentation, made by pressure to the affected area, does not persist. This type of oedema is mostly associated with lymphedema, lipoedema, and myxoedema. Read more about Different types of swelling you shouldn't ignore

Risk factors for edema

Risk factors for pitting edema include:

• Immobility, that is, standing or sitting for a long period
• Varicose veins
• Injury or surgery
• Burns to the skin
• Obesity
• Malnutrition
• pregnancy
• Drugs: Nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids. Vasodilators such as hydralazine and minoxidil can cause oedema because of significant sodium retention.Antihypertensive drugs such as beta-blockers, central alpha-agonists, and peripheral alpha-blockers may cause oedema, particularly in high doses. [2]

Some medical conditions are also associated with oedema. Here s a 101 on some of them.

Chronic kidney disease (CKD) associated edema

People in early stages of CKD are generally asymptomatic. Symptoms start manifesting only at the later stages (4 or 5) of CKD when water and electrolyte balance is disrupted. Peripheral edema and sometimes lung edema, manifest in CKD patients.

Symptoms:

i. Accumulation of fluid in the feet and lower legs

ii. Puffiness around the eyes especially in the morning

iii. Abdominal swelling

Causes: One of the aspects of CKD is that proteins filter out of the kidney into urine, resulting in lower concentration of protein, specifically albumin, in the blood. The function of albumin is to maintain the fluid volume in the blood. Since albumin concentration reduces in CKD patients, protein-fluid balance is disturbed as the oncotic pressure decreases, resulting in edema. Secondly, kidneys cannot filter out extra water and salts, again resulting in water and salt retention.

Treatment:

1. Avoid salt intake; consume low sodium foods such as pumpkin, gourds, and brinjal.
2. Your doctor may prescribe loop diuretics such as furosemide to control edema. Do not take any medicine without first consulting with your doctor. Loop diuretics have several side effects in people with CKD. According to researchers, dose of furosemide differs according to the clinical condition of the patient. Generally, it is 80 mg to 160 mg in people with declining kidney function. [3]

Congestive heart failure associated edema / Pulmonary (lung) edema

Pulmonary edema is accumulation of fluid in the lungs, most often as a consequence of congestive heart failure, and it is a medical emergency. Lung edema develops because of left heart failure. Fluid accumulation in the legs and ankles is a sign of worsening heart failure.

Symptoms:

1. Swelling in the legs and ankle, especially later in the day. Lying down and resting for some time will reduce the swelling.
2. Extreme breathlessness and a feeling of drowning
3. Cough is an early sign of worsening lung edema due to heart failure
4. Pink, frothy sputum is a sign when the disease becomes severe.

Pulmonary edema not related to heart failure / non-cardiogenic pulmonary edema

Lung edema is not always a result of congestive heart failure. It can also occur because of either direct lung injury such as inhalation of corrosive gases or near drowning, or indirect lung injury such as in pancreatitis, pneumonia, severe burns, and multiple blood transfusions.

The protein-rich fluid leaks into the interstitial and alveolar (small sac like structures in the lungs) spaces and causes edema.

Symptoms:

1. Extreme shortness of breath
2. Feeling of drowning

The difference between cardiogenic and non-cardiogenic lung edema is that in the first one, edema occurs as a result of increased capillary hydrostatic pressure, whereas in the latter case, edema results because of increased permeability of the inner layer of the alveoli. [4]

Cerebral edema

Brain edema is a swelling in the brain caused by trauma to the brain, stroke, haemorrhages, tumour, allergy, infections such as meningitis and encephalitis, and many other factors. Whatever the cause of the swelling, it is a life threatening condition that requires immediate medical attention.

Symptoms:

1. Headache
2. Nausea and vomiting
3. Dizziness
4. Stiffness in the neck
5. Memory loss, difficulty speaking, inability to walk
6. Loss of consciousness

Cirrhosis associated edema

Cirrhosis is a liver disease in which healthy liver tissue is progressively replaced with scar tissue, preventing the liver to function properly. The scar tissue blocks the flow of blood and slows the production of proteins and other substances in the liver. Decrease in protein production decreases oncotic pressure. As a result, fluid leaks into surrounding tissues. When the fluid accumulates in the abdominal cavity it is called ascites. Other than that, fluid can also accumulate in lower limbs and even chest cavity as edema.

Symptoms:

1. Significant discomfort, especially in the abdominal region
2. Abdominal distention
3. Shortness of breath

Management of ascites:

1. Bed rest; according to a study, upright position in cirrhotic patients impairs renal blood perfusion and causes sodium retention. [5]
2. Restrict water intake.
3. Restrict salt intake to 2 g/day in the diet. [5]

Treatment generally includes diuretic therapy, large volume paracentesis (LVP), and shunt placement. Treatment with diuretic therapy is initiated with moderate (grade 2) ascites. Later stages required LVP intervention along with diuretic therapy.

Lymphedema

When the lymph system is damaged or blocked, the fluid builds up in the tissues and causes swelling. It is a problem that is normally caused by cancer or cancer treatment. Lymphedema usually occurs in the arms or legs, but it can happen in any part of the body.

Symptoms:

1. Swelling of a limb, including fingers and toes
2. Trouble moving a joint in the arm or leg
3. Itching or burning feeling in the legs
4. A feeling of tightness when wearing clothes or shoes
5. Trouble sleeping

Cause:

Lymph, which is a clear fluid that fights against infection in the body, lymph vessels, and lymph nodes are directly involved in the formation of edema. Fluid leaks out of the capillaries and flows around body tissues. Part of it is absorbed by the blood stream and the rest flows back into the lymphatic system. When the lymph system does not function properly, fluid cannot drain from nearby tissues, resulting in edema. Read more about How to treat swollen feet naturally?

During the first stage of lymphedema, pressing on the swollen area leaves an indent (pitting edema), and the limbs feel spongy. In the second stage, fibrosis may develop and the limb may feel hard. Indent is not formed when the area is pressed (non-pitting edema).

Treatment:

You cannot treat lymphedema; you need to see the doctor as soon as possible. You can, however, take preventive measures.

1. Treat cuts and breaks in the skin with antibacterial ointment.
2. Avoid needle sticks to the affected limb. This includes shots and blood tests.
3. Avoid blocking flow of fluids through the body. For example, do not sit with your legs crossed, or do not wear stocking or clothing with tight band, or do not carry bags or articles with the affected arm.
4. Do not apply heat to the affected limb.

Idiopathic edema

If you don t have a kidney disease or cardiovascular problems; you are not overweight or diabetic, and your liver, lungs and thyroid function are normal, but you have water retention symptoms, you may be diagnosed with idiopathic edema, which means an edema with unknown cause.

It mainly affects middle-aged women and the gets worse with age.

Symptoms: Fluid retention throughout the day, but especially so on waking up in the morning which improves later in day.

Causes: Although what causes idiopathic edema is not clear, common causes include

i. Standing for long period of time

ii. Long journeys or sitting still for long periods

iii. Binge eating alternating with strict dieting

iv. Allergies, for example, gluten allergy

v. Cellulite

Treatment:

There is no cure for idiopathic edema since the exact cause of the edema is not known.

For edema due to cellulite, researchers at Godoy Clinic, Brazil, treated their patients with 75 mg of aminaphtone for 6 months, and if the condition didn t improve by then, treatment with ginkgo biloba was prescribed. [6]

In general, reducing salt intake could help improve edema. Cut down on processed food. Potassium rich foods such as banana and tomato actually help reduce the salt level in the body. Do not take potassium as supplements. This will harm you rather than help you.

For some people, excluding gluten foods, such as wheat, can help improve the condition. In others, reducing weight does the work. Support stocking and regular exercise are also beneficial.

Reference

1. Wiig H, Swartz MA; Interstitial fluid and lymph formation and transport: physiological regulation and roles in inflammation and cancer. Physiol Rev. 2012 Jul;92(3):1005-60. doi: 10.1152/physrev.00037.2011.

2. Sica DA. Calcium channel blocker-related peripheral edema: can it be resolved? ClinHypertens (Greenwich) 2003; 5: 291 295.

3. Oh SW, Han SY. Loop Diuretics in Clinical Practice. Electrolytes & Blood Pressure : E & BP. 2015;13(1):17-21. doi:10.5049/EBP.2015.13.1.17.

4. Murray, J. F. Pulmonary edema: pathophysiology and diagnosis [Review article]. The International Journal of Tuberculosis and Lung Disease. 2011, 15:2 pp 155-160(6).

5. Kashani, A. et al. "Fluid Retention In Cirrhosis: Pathophysiology And Management". QJM 101.2 (2008): 71-85.
6. De Godoy JMP, de Godoy M de FG. Evaluation of the Prevalence of Concomitant Idiopathic Cyclic Edema and Cellulite. International Journal of Medical Sciences. 2011;8(6):453-455.

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