Edema is the medical term for swelling. It is a general response of the body to injury or inflammation. Edema can be isolated to a small area or affect the entire body.
Edema results whenever small blood vessels become "leaky" and release fluid into nearby tissues. The extra fluid accumulates, causing the tissue to swell.
Types of Edema
Clinically there are two types of edema –
pitting and
non-pitting edema.
Pitting edema is the term used to describe edema when pressure applied to the skin of the swollen area is released and an indentation is left behind (e.g. when the skin is pressed with a finger or when stockings or socks induce indentation). Non-pitting edema is the term used to describe edema when this pressure-induced indentation does not occur.
Non-pitting edema usually
occurs in the arms and legs.
Occasionally pitting edema and non-pitting edema can occur without an underlying disease and it is then known as idiopathic edema.
This is most common in women who experience it in their legs and feet when they are pre-menstrual or pre-menopausal – it is then often known as cyclical edema.
Symptoms of Edema?
Symptoms of edema may include:
Persistent indentation of the skin (Pitting)Swelling
Swollen feet, ankles and legs
Painful skin sensations such as burning, soreness, tingling Numbness Cramps
Water retention or interstitial fluid Puffiness
Abdominal bloating
Night sweats
Skin that is warm or hot to the touch
Causes of Edema
Edema is a normal response of the body to inflammation or injury.
For example,
a twisted ankle,
a bee sting, or a skin infection
will all result in edema in the involved area i.e UNILATERAL.
In some cases, such as in an infection, this may be beneficial. Increased fluid from the blood vessels allows more infection-fighting white blood cells to enter the affected area.
Edema can also result from medical conditions or problems in the balance of substances normally present in blood. Some of the causes of edema include:(BILATERAL)
Hypoalbuminemia:
Albumin and other proteins in the blood act like sponges to keep fluid in the blood vessels. Low albumin may contribute to edema, but isn't usually the sole cause.
Allergic reactions:
Edema is a usual
component of most allergic reactions. In response to the allergic exposure, the body allows nearby blood vessels to leak fluid into the affected area.(UNILATERAL)
Obstruction of flow:
If the drainage of fluid from a body part is blocked, fluid can back up.
A blood clot in the deep veins of the leg can result in leg edema.
A tumor blocking lymph or blood flow will cause edema in the affected area.(UNILATERAL)
Critical illness:
Burns, life-threatening infections, or other critical illnesses can cause a whole-body reaction that allows fluid to leak into tissues almost everywhere. Widespread edema throughout the body can result.
Edema and heart disease (CCF):
When the heart weakens and pumps blood less effectively, fluid can slowly build up, creating leg edema. If fluid buildup occurs rapidly, fluid in the lungs (pulmonary edema) can develop. If there is heart failure of the right side of the heart, often times edema can develop in the abdomen, as well.
Edema and liver disease:
Severe liver disease (cirrhosis) results in an increase in fluid retention. Cirrhosis also leads to low levels of albumin and other proteins in the blood. Fluid leaks into the abdomen i.e ascites, and can also produce leg edema.
Edema and kidney disease:
A kidney condition like nephrotic syndrome can result in severe leg edema, and sometimes whole-body edema (anasarca).
Edema and pregnancy:
Due to an increase in blood volume during pregnancy and pressure from the growing womb, mild leg edema is common during pregnancy. However, serious complications of pregnancy such as DVT and Preeclampsia can also cause edema.
Cerebral edema (brain edema):
Swelling in the brain can be caused by
head trauma,
hyponatremia,
high altitude,
brain tumors, or
an obstruction to fluid drainage (hydrocephalus).
Headaches, confusion, and unconsciousness or coma can be symptoms of cerebral edema.
Medications and edema: Numerous medications can cause edema, including:
NSAIDs:ibuprofen, naproxen
Calcium channel blockers
Corticosteroids (prednisone, methylprednisolone)
Pioglitazone and rosiglitazone
Pramiprexole
Edema in Children & Infants
Most incidences of edema in children and infants are related to serious health conditions, so changes in a child pt should be monitored to avoid complications.
Children with acute or chronic upper airway obstruction are at risk for negative-pressure pulmonary edema, associated with upper airway obstruction. This condition may also occur after head injury, seizure, or accidental chemical ingestion or inhalation.
While quite rare, Nephrotic Syndrome, can cause edema in children. As the main symptom of NS, edema is commonly seen around one or both of the eyes, also referred to as periorbital edema, but may be found in other parts of the body such as the legs. Children with NS typically experience weight gain as a result of fluid accumulation.
A urine test can confirm the diagnosis.
Periorbital edema should be closely monitored, as it may be the result of a more serious condition, such as congestive heart failure and liver diseases. Other causes of periorbital edema in children and infants may include allergies or infections, such as conjunctivitis.
Children and infants with diabetes may also experience edema as a side effect from insulin treatment. However, children with diabetes should report this to their pediatrician, as it may be a symptom of cerebral edema, a rare but serious complication of diabetes.
Additional info on causes of edema.
*Pregnancy can cause edema in the legs as the uterus puts pressure on the vena cava, a major blood vessel that returns blood to the heart from the legs, and progesterone relaxes the walls of the blood vessels.
Fluid retention during pregnancy also can be caused by a more serious condition called pre-eclampsia.
High blood pressure (Hypertension),
liver, kidney and thyroid diseases can cause edema
Injuries
Being largely overweight or obese--Excess weight can put added pressure on the knee and ankle joints and the lower limbs.
Standing or sitting for long periods of time particularly in hot weather can cause excess fluid to accumulate in feet, ankles and lower legs.
Diabetes
Low protein levels in the blood caused by malnutrition. The proteins help to hold water inside the blood vessels so fluid does not leak out into the tissues. If a blood protein, called albumin, gets too low, fluid leaks out the blood vessels and edema occurs, especially in the feet, ankles and lower legs Dehydration
Flying (Air Travel)
Menopause
Low Blood Pressure
Menstruation
Overeating
Poor Circulation
Eating food with a high salt content.
Spider & Insect Bites
Congestive heart failure is a condition in which the heart can no longer pump efficiently, and causes fluid buildup in the lungs and other parts of the body. Swelling is often most visible in the feet and ankles.
Severe chronic (long-term) lung diseases, including emphysema and chronic bronchitis, increase pressure in the blood vessels that lead from the heart to the lungs. This pressure backs up in the heart and the higher pressure causes swelling in the legs and feet.
Tiny valves inside the veins of the legs can become weakened, causing a common problem called venous insufficiency. This makes it more difficult for the veins to pump blood back to the heart, and leads to varicose veins and a buildup of fluid.
Differential diagnosis and principles of care
Unilateral oedema indicates a local cause.
A sudden onset of oedema may be indicative of venous thrombosis, whereas in chronic oedema deep venous insufficiency should be suspected.
The possibility of a ruptured Baker’s cyst should also be borne in mind.
If deep vein thrombosis is suspected, the patient should be referred early to compression ultrasonography.
If the patient does not have any risk factors for deep vein thrombosis, a negative D-dimer result rules out venous thrombosis in practice, and no referral is needed.
The need for referral may, besides D-dimer assay, be decided with compression ultrasonography.
Bilateral oedema is often caused by heart failure,
deep vein insufficiency
or prolonged standing.
Leg oedema of cardiac origin is always accompanied by other symptoms or findings of heart failure.
Venous leg oedema may be associated with stasis dermatitis or varicose veins.
Obesity and work involving standing predispose to pitting oedema in the evenings.
If no heart or venous problem appears to be causing the oedema, the possibility of kidney or liver disease should be considered.
When a patient presents with bilateral leg oedema, and heart failure or venous stasis are not likely causes, the following laboratory investigations are recommended:
Full blood count
Urinary protein and
plasma creatinine
Plasma potassium and sodiumALT (oedema due to liver disease is common in alcoholics)
TSH, particularly if oedema is present elsewhere than in the legs and the swollen area does not reduce under pressure.
Fasting blood glucose
Serum albumin (less than 20 g/l will often give rise to oedema).
Bilateral pitting oedema in a woman less than 50 years of age, mainly occurring in the evenings, may be considered to be benign provided that there are no signs of venous insufficiency or systemic illness.
Abdominal ultrasonography as well as the consultation of a specialist physician (and CT scanning of the abdominal/pelvic region) should be considered for patients over 50 years of age if no aetiology can be confirmed for leg oedema and for younger patients in the presence of suspicious findings (unilateral leg oedema, signs and symptoms at the pelvic region, weight loss), particularly if the clinical picture is suggestive of lymphoedema of unknown cause.
The cancers that most frequently are associated with limb oedema are prostate cancer, ovarian cancer, lymphoma and kidney cancer.
Tips for the Prevention of Edema
*Follow a low salt diet
*Avoid drinking too many fluids
*If you are overweight or obese, try to lose weight and reduce the pressure on your lower limbs and joints
*Elevate your legs above the level of your heart to keep swelling down and improve blood flow
*If your ankles and feet are swollen during pregnancy, keep your legs elevated and lie on your side rather than your back
*When you do lie down, place a pillow under your legs
*Wear support or compression stockings to improve the flow of blood through the veins
*Avoid leg swelling on long trips by standing up and walking around often or get up every hour
*Exercise your feet and lower legs while sitting as this will help the veins move blood back toward the heart
*Avoid smoking and drinking alcohol
*Try massage therapy, which stimulates blood flow and improves circulation
Treatment of Edema
Treatment of edema often means treating the underlying cause of edema. For example, allergic reactions causing edema may be treated with antihistamines and corticosteroids.
Edema resulting from a blockage in fluid drainage can sometimes be treated by eliminating the obstruction:
A blood clot in the leg is treated with blood thinners, and the clot slowly breaks down; leg edema then resolves as fluid drainage improves.
A tumor obstructing a blood vessel or lymph flow can sometimes be reduced in size or removed with surgery, chemotherapy, or radiation.
Leg edema related to congestive heart failure or liver disease can be treated with a diuretic like furosemide (Lasix).
When urine output increases, more fluid drains from the legs back into the blood.
Maintaining a sodium-restricted diet will also help limit fluid retention associated with heart failure or liver disease.
Edema results whenever small blood vessels become "leaky" and release fluid into nearby tissues. The extra fluid accumulates, causing the tissue to swell.
Types of Edema
Clinically there are two types of edema –
pitting and
non-pitting edema.
Pitting edema is the term used to describe edema when pressure applied to the skin of the swollen area is released and an indentation is left behind (e.g. when the skin is pressed with a finger or when stockings or socks induce indentation). Non-pitting edema is the term used to describe edema when this pressure-induced indentation does not occur.
Non-pitting edema usually
occurs in the arms and legs.
Occasionally pitting edema and non-pitting edema can occur without an underlying disease and it is then known as idiopathic edema.
This is most common in women who experience it in their legs and feet when they are pre-menstrual or pre-menopausal – it is then often known as cyclical edema.
Symptoms of Edema?
Symptoms of edema may include:
Persistent indentation of the skin (Pitting)Swelling
Swollen feet, ankles and legs
Painful skin sensations such as burning, soreness, tingling Numbness Cramps
Water retention or interstitial fluid Puffiness
Abdominal bloating
Night sweats
Skin that is warm or hot to the touch
Causes of Edema
Edema is a normal response of the body to inflammation or injury.
For example,
a twisted ankle,
a bee sting, or a skin infection
will all result in edema in the involved area i.e UNILATERAL.
In some cases, such as in an infection, this may be beneficial. Increased fluid from the blood vessels allows more infection-fighting white blood cells to enter the affected area.
Edema can also result from medical conditions or problems in the balance of substances normally present in blood. Some of the causes of edema include:(BILATERAL)
Hypoalbuminemia:
Albumin and other proteins in the blood act like sponges to keep fluid in the blood vessels. Low albumin may contribute to edema, but isn't usually the sole cause.
Allergic reactions:
Edema is a usual
component of most allergic reactions. In response to the allergic exposure, the body allows nearby blood vessels to leak fluid into the affected area.(UNILATERAL)
Obstruction of flow:
If the drainage of fluid from a body part is blocked, fluid can back up.
A blood clot in the deep veins of the leg can result in leg edema.
A tumor blocking lymph or blood flow will cause edema in the affected area.(UNILATERAL)
Critical illness:
Burns, life-threatening infections, or other critical illnesses can cause a whole-body reaction that allows fluid to leak into tissues almost everywhere. Widespread edema throughout the body can result.
Edema and heart disease (CCF):
When the heart weakens and pumps blood less effectively, fluid can slowly build up, creating leg edema. If fluid buildup occurs rapidly, fluid in the lungs (pulmonary edema) can develop. If there is heart failure of the right side of the heart, often times edema can develop in the abdomen, as well.
Edema and liver disease:
Severe liver disease (cirrhosis) results in an increase in fluid retention. Cirrhosis also leads to low levels of albumin and other proteins in the blood. Fluid leaks into the abdomen i.e ascites, and can also produce leg edema.
Edema and kidney disease:
A kidney condition like nephrotic syndrome can result in severe leg edema, and sometimes whole-body edema (anasarca).
Edema and pregnancy:
Due to an increase in blood volume during pregnancy and pressure from the growing womb, mild leg edema is common during pregnancy. However, serious complications of pregnancy such as DVT and Preeclampsia can also cause edema.
Cerebral edema (brain edema):
Swelling in the brain can be caused by
head trauma,
hyponatremia,
high altitude,
brain tumors, or
an obstruction to fluid drainage (hydrocephalus).
Headaches, confusion, and unconsciousness or coma can be symptoms of cerebral edema.
Medications and edema: Numerous medications can cause edema, including:
NSAIDs:ibuprofen, naproxen
Calcium channel blockers
Corticosteroids (prednisone, methylprednisolone)
Pioglitazone and rosiglitazone
Pramiprexole
Edema in Children & Infants
Most incidences of edema in children and infants are related to serious health conditions, so changes in a child pt should be monitored to avoid complications.
Children with acute or chronic upper airway obstruction are at risk for negative-pressure pulmonary edema, associated with upper airway obstruction. This condition may also occur after head injury, seizure, or accidental chemical ingestion or inhalation.
While quite rare, Nephrotic Syndrome, can cause edema in children. As the main symptom of NS, edema is commonly seen around one or both of the eyes, also referred to as periorbital edema, but may be found in other parts of the body such as the legs. Children with NS typically experience weight gain as a result of fluid accumulation.
A urine test can confirm the diagnosis.
Periorbital edema should be closely monitored, as it may be the result of a more serious condition, such as congestive heart failure and liver diseases. Other causes of periorbital edema in children and infants may include allergies or infections, such as conjunctivitis.
Children and infants with diabetes may also experience edema as a side effect from insulin treatment. However, children with diabetes should report this to their pediatrician, as it may be a symptom of cerebral edema, a rare but serious complication of diabetes.
Additional info on causes of edema.
*Pregnancy can cause edema in the legs as the uterus puts pressure on the vena cava, a major blood vessel that returns blood to the heart from the legs, and progesterone relaxes the walls of the blood vessels.
Fluid retention during pregnancy also can be caused by a more serious condition called pre-eclampsia.
High blood pressure (Hypertension),
liver, kidney and thyroid diseases can cause edema
Injuries
Being largely overweight or obese--Excess weight can put added pressure on the knee and ankle joints and the lower limbs.
Standing or sitting for long periods of time particularly in hot weather can cause excess fluid to accumulate in feet, ankles and lower legs.
Diabetes
Low protein levels in the blood caused by malnutrition. The proteins help to hold water inside the blood vessels so fluid does not leak out into the tissues. If a blood protein, called albumin, gets too low, fluid leaks out the blood vessels and edema occurs, especially in the feet, ankles and lower legs Dehydration
Flying (Air Travel)
Menopause
Low Blood Pressure
Menstruation
Overeating
Poor Circulation
Eating food with a high salt content.
Spider & Insect Bites
Congestive heart failure is a condition in which the heart can no longer pump efficiently, and causes fluid buildup in the lungs and other parts of the body. Swelling is often most visible in the feet and ankles.
Severe chronic (long-term) lung diseases, including emphysema and chronic bronchitis, increase pressure in the blood vessels that lead from the heart to the lungs. This pressure backs up in the heart and the higher pressure causes swelling in the legs and feet.
Tiny valves inside the veins of the legs can become weakened, causing a common problem called venous insufficiency. This makes it more difficult for the veins to pump blood back to the heart, and leads to varicose veins and a buildup of fluid.
Differential diagnosis and principles of care
Unilateral oedema indicates a local cause.
A sudden onset of oedema may be indicative of venous thrombosis, whereas in chronic oedema deep venous insufficiency should be suspected.
The possibility of a ruptured Baker’s cyst should also be borne in mind.
If deep vein thrombosis is suspected, the patient should be referred early to compression ultrasonography.
If the patient does not have any risk factors for deep vein thrombosis, a negative D-dimer result rules out venous thrombosis in practice, and no referral is needed.
The need for referral may, besides D-dimer assay, be decided with compression ultrasonography.
Bilateral oedema is often caused by heart failure,
deep vein insufficiency
or prolonged standing.
Leg oedema of cardiac origin is always accompanied by other symptoms or findings of heart failure.
Venous leg oedema may be associated with stasis dermatitis or varicose veins.
Obesity and work involving standing predispose to pitting oedema in the evenings.
If no heart or venous problem appears to be causing the oedema, the possibility of kidney or liver disease should be considered.
When a patient presents with bilateral leg oedema, and heart failure or venous stasis are not likely causes, the following laboratory investigations are recommended:
Full blood count
Urinary protein and
plasma creatinine
Plasma potassium and sodiumALT (oedema due to liver disease is common in alcoholics)
TSH, particularly if oedema is present elsewhere than in the legs and the swollen area does not reduce under pressure.
Fasting blood glucose
Serum albumin (less than 20 g/l will often give rise to oedema).
Bilateral pitting oedema in a woman less than 50 years of age, mainly occurring in the evenings, may be considered to be benign provided that there are no signs of venous insufficiency or systemic illness.
Abdominal ultrasonography as well as the consultation of a specialist physician (and CT scanning of the abdominal/pelvic region) should be considered for patients over 50 years of age if no aetiology can be confirmed for leg oedema and for younger patients in the presence of suspicious findings (unilateral leg oedema, signs and symptoms at the pelvic region, weight loss), particularly if the clinical picture is suggestive of lymphoedema of unknown cause.
The cancers that most frequently are associated with limb oedema are prostate cancer, ovarian cancer, lymphoma and kidney cancer.
Tips for the Prevention of Edema
*Follow a low salt diet
*Avoid drinking too many fluids
*If you are overweight or obese, try to lose weight and reduce the pressure on your lower limbs and joints
*Elevate your legs above the level of your heart to keep swelling down and improve blood flow
*If your ankles and feet are swollen during pregnancy, keep your legs elevated and lie on your side rather than your back
*When you do lie down, place a pillow under your legs
*Wear support or compression stockings to improve the flow of blood through the veins
*Avoid leg swelling on long trips by standing up and walking around often or get up every hour
*Exercise your feet and lower legs while sitting as this will help the veins move blood back toward the heart
*Avoid smoking and drinking alcohol
*Try massage therapy, which stimulates blood flow and improves circulation
Treatment of Edema
Treatment of edema often means treating the underlying cause of edema. For example, allergic reactions causing edema may be treated with antihistamines and corticosteroids.
Edema resulting from a blockage in fluid drainage can sometimes be treated by eliminating the obstruction:
A blood clot in the leg is treated with blood thinners, and the clot slowly breaks down; leg edema then resolves as fluid drainage improves.
A tumor obstructing a blood vessel or lymph flow can sometimes be reduced in size or removed with surgery, chemotherapy, or radiation.
Leg edema related to congestive heart failure or liver disease can be treated with a diuretic like furosemide (Lasix).
When urine output increases, more fluid drains from the legs back into the blood.
Maintaining a sodium-restricted diet will also help limit fluid retention associated with heart failure or liver disease.
