Swelling (Edema)

Oedema is a condition in which there is an abnormal collection of fluid in the body or a part of the body. It can result from local as well as systemic problems. Oedema frequently occurs in the arms and legs, with the legs being more commonly affected than the arms. This is because the circulation of blood from the legs to the heart occurs against gravity. Slow and sluggish blood circulation through veins in the legs leads to the leakage of fluid from the blood, which collects in the surrounding tissues and results in oedema. Damage to the lymphatic system or removal of the lymph nodes (such as in cancer treatment) and varicose veins usually cause oedema in one leg. Disorders related to the kidneys, heart, lungs and liver, pregnancy, menstrual periods, prolonged standing and anaemia lead to generalised oedema. Additionally, chronic swelling in the legs is commonly associated with old age and obesity. Long-standing peripheral oedema can lead to an infection in the legs (such as cellulitis) or ulcer formation, especially in the elderly.

In India, the incidence of heart failure is 1.3 to 4.6 million, which is an important cause of oedema. Moreover, in the last 30 years, there has been a significant increase in the number of people with liver and kidney disease, which leads to peripheral and pedal oedema. Oedema due to venous problems (varicose veins and deep vein thrombosis) occurs in 1 out of 5 people in India. Filariasis is an infection spread by mosquitoes, which affects the lymphatic system of the body. As a result, oedema occurs in one or both the legs, which is medically known as elephantiasis. 

Classification of oedema can be done in various ways, such as:

Based on the location

• Generalised Oedema
  Puffiness or swelling all over the body (anasarca).
• Localised Oedema
  Oedema in a particular body part, such as:
  • Peripheral oedema (oedema in the arms and legs).
  •  Pedal oedema (oedema in the legs).
  •  Dependent oedema (sacral oedema), occurs in the dependent areas of the body, such as the lower back and buttocks in chronically bedridden patients.
  •  Pulmonary oedema (oedema in the lungs).
  •  Macular oedema (oedema in the eyes).
  •  Cerebral oedema (oedema in the brain).
  •  Ascites (oedema in the abdomen).

Based on distribution

• Unilateral
  Oedema occurs only in one leg. Examples of the diseases, which present as unilateral oedema include deep vein thrombosis, cellulitis, compartment syndrome, venous insufficiency or varicose veins, and lymphedema.
• Bilateral
  Both legs are swollen in bilateral oedema. Examples include oedema due to medicines and allergy, heart failure, liver disease, kidney disease, obstructive sleep apnea, varicose veins, lymphedema, tumour. Sometimes, the underlying cause of bilateral oedema remains unknown. In medical terms, it is called idiopathic oedema.

Based on its depressible nature

• Pitting Oedema
   A depression or pit is formed in the swollen area on applying pressure with a finger, which stays even after the pressure is removed. This is called pitting oedema. The depression in the oedematous skin usually fills up within 5 seconds after removing the pressure.
• Non-pitting Oedema
  Commonly seen in oedema, which occurs due to a blockage in the lymphatic system. In non-pitting oedema, a dent doesn’t appear on applying pressure on the swollen body part.

Certain signs and symptoms appear in the body as oedema progresses. These include:

• The leg or affected parts swell up or become puffy.
• There is a change in the colour of the skin in the swollen area.
• The oedematous area pits or shows a dent when pressure is applied by a finger (pitting oedema). In the majority of cases, oedema is pitting except in lymphedema, which occurs due to cancer, damaged lymph nodes due to radiation therapy, and thyroid disorders (myxoedema due to hypothyroidism).
• The affected body part feels heavy and difficult to move when joints are also involved.
• The skin of the swollen area becomes warm and stretchy. In generalised oedema, it becomes uncomfortable to wear clothes.
• In cases of oedema due to a clot in the vein or varicose veins, the affected leg becomes tender and painful.
• Breathlessness is a symptom associated with oedema that occurs due to heart failure, kidney disease, liver problems or lung disorder.
• Weight gain commonly accompanies generalised oedema.

Causes

Multiple systemic and local causative factors are responsible for both generalised and local oedema.

Localized Oedema

• Increased permeability of the capillaries
  Leakage of fluid through the wall of the blood vessels leads to its accumulation in the surrounding tissues. This occurs in:
  • Infections (cellulitis).
  • Allergy.
  • Certain medicines used for treating high blood pressure and hormonal disorders.
• Increased fluid (hydrostatic) pressure in the capillaries
  An increase in blood pressure in the capillaries forces some fluid out of the blood vessel leading to oedema. This occurs in:
  • Chronic circulatory problems in the veins of the legs.
  • Conditions where there is an increase in the pressure in the leg muscles due to internal bleeding after an injury (compartment syndrome).
  • Congestive heart failure.
  • Kidney failure.
  • Pregnancy.
  • Anaemia.
• Sleep apnea
  An increased blood pressure in the lungs due to sleep apnea (a serious respiratory disorder in which breathing starts and stops repeatedly during sleep) also results in peripheral oedema.
• Lymphatic vessel obstruction
  Blockage in the lymphatic system of the body results in unilateral and bilateral pedal oedema. Lymphatic vessels drain excess fluid that collects in the tissues of the body. Blockage in the flow of lymph can be present at birth or may occur due to a tumour, injury, radiation therapy for cancer treatment, and infections, such as filariasis.
• Obesity
  Excess fat in the tissues results in an abnormal accumulation of fluid in one or both the legs (lipoedema).
• Menstrual cycle
  Idiopathic oedema is a swelling in the legs with no definite cause. This occurs in women during menstrual periods.
• Long standing or sitting hours
  Oedema in both legs is generally seen after long hours of standing or sitting in one position.

In these conditions, oedema can occur in one or both the legs depending on the severity of the problem. In severe cases, oedema may also occur all over the body.

Generalized Oedema

• Low serum protein levels
  A decrease in the blood serum protein levels (albumin) leads to leakage of fluid out of the blood vessels. As a result, oedema usually occurs in both the legs or all over the body depending on the intensity of the problem. This occurs in:
  • Having a diet low in proteins.
  • Chronic liver diseases.
  • Kidney problems (nephrotic syndrome).
  • Intestinal disorders involving problems with the absorption of proteins.
• Thyroid disorders
  Thyroid gland problems such as hypothyroidism also cause oedema in the arms and legs. In a severe case of hypothyroidism, oedema occurs all over the body, which is called myxoedema in medical terms.
• Pregnancy
  Generalised oedema or oedema in both the legs is common during pregnancy, which may or may not be associated with high blood pressure.

Risk factors

Certain conditions increase the risk of developing oedema. These include:

• Pregnancy.
• Being overweight.
• Medicines such as antihypertensives (such as calcium channel blockers), which are used to control high blood pressure.
• Prolonged lying position as in chronically ill and bedridden patients.
• Job or work that demands prolonged hours of standing or sitting.
• A diet low in proteins.
• Anaemia.

Different measures help in preventing oedema in people who are at a higher risk of developing it. Some of them are listed below:

• Compression stockings or flight stockings during long travel hours help in preventing the development of deep vein thrombosis in people suffering from varicose veins and subsequently the development of oedema.
• Mild to moderate compression stockings help in preventing pedal oedema and deep vein thrombosis during pregnancy.
• Physical activity such as moderate exercises also helps in preventing oedema in the legs in women during pregnancy.
• Adequate skin care measures should be taken to avoid infections from injuries and insect bites. Habits such as keeping the skin moist, avoiding hot water baths and using correct fitting shoes help in preventing lymphedema in the legs in high-risk individuals.
• Following a salt-restricted diet before helps in preventing oedema.
• Smoking and alcohol cessation helps in preventing diseases, which are usually associated with oedema, such as congestive heart failure, liver diseases and high blood pressure.
• Taking frequent breaks by walking or sitting down in jobs that demand prolonged standing hours helps in preventing oedema in the legs. Long sitting hours should be interspersed with short walks or standing once after every hour.

The diagnosis of oedema is established by:

Medical history

Medical history regarding the onset and location (unilateral or bilateral) of oedema, medications and illnesses helps to evaluate the cause of oedema.

Physical examination

Physical examination plays an important role in the diagnosis of oedema. The doctor will conduct a thorough examination to confirm the presence of oedema. He will look for signs to diagnose the underlying cause of the disease that is leading to oedema.

Investigations

• Blood tests
  Blood tests are carried out to diagnose oedema due to systemic diseases.
  • Brain natriuretic peptide test is performed to identify congestive heart failure.
  • Serum creatinine and urine test are performed to check for the presence of any kidney diseases resulting in oedema.
  • Serum albumin and liver enzymes tests are done to rule out liver disorders.
  • D-dimer test is used for diagnosing deep vein thrombosis as the cause of oedema.
  • Complete blood count (CBC) is used for the detection of anaemia and infections.
  • Thyroid profile for identifying the presence of an underlying thyroid disorder.
• Ultrasonography 
  It helps in detecting a clot and any other circulatory disorder of the veins. Compression ultrasonography with Doppler imaging is performed to confirm the exact location of the blood clot in the vein.
• Lymphoscintigraphy
  Blockage in the lymphatic system is diagnosed by injecting a radioactive dye in the lymphatic vessels.
• Magnetic resonance imaging (MRI)
  MRI helps to confirm the diagnosis of deep vein thrombosis. Magnetic resonance lymphangiography is carried out to view the lymphatic vessels and evaluate the cause of lymphedema.
• Echocardiography
  Echocardiography is performed in people with oedema due to sleep apnea to evaluate high blood pressure in the lungs.
• Electrocardiogram (ECG) and chest X-ray
  These tests help in diagnosing heart failure, tumour or oedema in the lungs, and other related diseases.

The treatment and management of oedema depend upon its underlying cause and may employ the following strategies:

• Keeping the legs in a raised position, especially while lying down and using compression stockings helps to reduce oedema in the initial stages. Stockings are avoided in those who have hard or narrow leg arteries due to plaque formation (atherosclerosis). In such cases, an electronic device called a pneumatic compression device is used to prevent clot formation. A pneumatic device is contraindicated in people with leg ulcers, burns or peripheral blood vessel diseases. The cuffs are wrapped around the legs and filled with air. This squeezes the tissues and promotes blood flow through the veins thus preventing the formation of blood clots.
• Medicines, which increase the frequency of urination and drain excess water from the body, known as diuretics, are used when congestive heart failure accompanies venous insufficiency.
• Skin care is an important component of oedema that occurs due to venous insufficiency. Moisturising creams and mild corticosteroid ointments help in preventing dryness and reducing inflammation in the skin over the swollen area.
• Deep vein thrombosis is treated by using anticoagulants or clot-burster medicines (heparin or warfarin), which are used to dissolve the blood clot in the leg. Stockings and bandages help in preventing the formation of blood clot in individuals suffering from chronic venous insufficiency and deep vein thrombosis.
• In lymphedema, physiotherapy, external massage, and bandages are used to stimulate circulation and clear the blockage in the lymphatic vessel which subsequently helps in reducing oedema. A pneumatic compression device is more effective in reducing oedema to a significant extent in lymphedema. Surgery to bypass the blocked lymphatic vessel, medically known as surgical debulking, is performed when lymphedema fails to respond to different treatment measures.
• In the case of medicine-induced oedema, other medicines, such as angiotensin-converting enzyme inhibitors or ACE inhibitors are used instead of calcium channel blockers for the treatment of high blood pressure, which commonly results in oedema in both the legs.
• Oedema due to liver diseases, kidney problems and intestinal disorders that lead to protein loss are treated with protein injections, restriction in the intake of salt and water in the initial stages, and diuretics.
• Weight reduction and the use of continuous positive air pressure device (CPAP) improves the lung function and helps in reducing oedema in the legs due to sleep apnea.
• Oedema in the legs without a known cause (idiopathic oedema) is treated with medicines called aldosterone antagonists besides other lifestyle modification measures.
• In the case of oedema that is caused due to an injury,  systemic steroids and tricyclic antidepressant medicines are used for relieving pain and swelling.

Lifestyle management

Simple measures can help manage oedema on a daily basis:

• Reducing the intake of salt and sugar in the diet can help reduce water retention and oedema.
• Walking, jogging, leg raises and other exercises help improve blood circulation, and thereby help reduce oedema.
• Get regular massage done to improve blood circulation and increase the blood flow towards the heart.
• Eat a healthy and balanced diet to prevent and control weight gain.
• Avoid smoking and alcohol consumption.
• Get a complete body checkup once every six months to rule out the presence of any diseases. 

Prognosis

The outcome usually depends on the cause of oedema and is generally good. It usually resolves in most of the cases. However, in lymphedema, which is causes due to filarial infection, oedema persists for a long time due to the complete blockage of the lymphatic vessels. Lymphedema that develops after surgery resolves within a week with self-care. Severe damage to the lymphatic system caused by radiations results in chronic oedema or recurrent oedema.

Complications

A chronic and severe form of oedema due to specific reasons needs medical treatment. Complications develop when oedema progresses further or is left untreated. Some of these complications include:

• Infection
  Cellulitis or infection is the most common complication of chronic oedema and lymphedema. The swollen area becomes red, warm, and develops pus. Fever generally accompanies cellulitis.
• Itching and cracks in the skin
  In chronic oedema, the skin in the swollen area gets inflamed, along with a change in its colour due to the breakdown of haemoglobin in the blood. As a result, there is a development of eczema in the affected skin which can further get infected in absence of suitable treatment.
• Ulcer
  Development of an ulcer is also a common complication of chronic oedema, which commonly occurs due to problems in the venous circulation of the legs (venous insufficiency). The risk of infection in the ulcer increases in the absence of early treatment and care.