Edema is swelling due to an accumulation of excess fluid. Your body has set fluid levels and will restore itself to its usual state within 48 hours of taking in extra water under normal circumstances. There are many causes and subtypes of edema including hypertensive, exercise, high altitude, tropical, medication and idiopathic cyclic edema.
The body's cells exist in a pool of water called interstitial fluid, which suspends the cells and provides a medium for them to interact with one another. Capillaries (small blood vessels) supply the interstitial fluid with nutrients and oxygen. The capillaries also carry away the cells' waste products. Edema occurs when the volume of interstitial fluid is greater than normal.
Because of gravity, edema is most common in the ankles, feet, and legs.
Idiopathic Cyclic Edema is one subtype primarily occurring in young menstruating women in which large amounts of tissue swelling occurs in the legs and abdomen after sitting or standing, and swelling of the face and eyelids upon lying down. It is thought to be a problem of leakage of blood fluids from capillaries into fat and skin tissue especially when gravity (standing up) is added to the pressure in the vascular system. It results in large weight changes from morning to evening. Sometimes the condition is called idiopathic orthostatic (standing upright) edema or just idiopathic edema. Other names include fluid retention syndrome and cyclical edema.
Swelling in both legs can have many other possible causes:
Idiopathic Cyclic Edema can result in moderate discomfort in any area of excess fluid accumulation. Carpal tunnel syndrome, diffuse aching, morning stiffness and muscle/bone pains as well as headaches often accompany the swelling. It can also masquerade as premenstrual syndrome or make existing premenstrual syndrome worse. It exacerbates the swelling, abdominal bloating and general physical discomfort but it does not usually cause irritability or depressive symptoms as does classic PMS.
To check for edema that is not obvious, you can gently press your thumb over the foot, ankle or leg with slow, steady pressure. If edema is present, an indentation will show on the skin. A professional evaluation to determine the cause of leg swelling is needed. If both legs are swollen, your doctor will inquire about other symptoms and perform a physical examination. A urine test will show whether you are losing protein from the kidneys. Blood tests, a chest X-ray and an electrocardiogram (ECG) may be ordered.
Treatment focuses on correcting the underlying cause of the fluid accumulation. In addition, a low-salt diet and avoiding excess fluid intake usually helps. If you are not short of breath, elevation of the legs above the level of your heart will also keep swelling down. A low dose of a diuretic (water pill) used sparingly might be added in some cases.
For swollen ankles and feet caused by pregnancy from the enlarged uterus pushing on the vena cava, elevation of the legs and not lying on your back (either side) helps blood flow and decreases swelling.
Most patients with mild leg edema due to varicose veins can be treated with periodic leg elevation and support (compression) stockings. Sometimes surgery is needed to improve the flow of blood through the leg veins.
Also, no matter what the underlying cause of edema, any swollen area of the body should be protected from pressure, injury and extreme temperatures. The skin over swollen legs becomes more fragile over time. Cuts, scrapes and burns take much longer to heal and are more prone to infection when skin has edema underneath.
Prevention of edema means preventing the cause. Smoking is the No. 1 cause of chronic lung disease. Congestive heart failure most often is due to coronary artery disease and high blood pressure. To avoid leg swelling on long trips or due to long hours at a desk job, stand up and walk around often; ideally you should get up once per hour. If not possible, then exercise your feet and lower legs while sitting. This will help the veins move blood back toward the heart.
When you repeatedly take laxatives, diuretics or vomit, your body will adapt to being constantly dehydrated by learning to retain more fluid than usual. When you stop these behaviors and start to take a normal diet, your body may continue to retain fluids until it learns that adequate fluid will be available, then it will release the extra fluid. People who abuse laxatives or vomit regularly are at the greatest risk for alternating between dehydration and edema.
The prognosis for edema of the legs depends on the cause. For most people with edema, the prognosis is excellent. It may take from 2 to 6 weeks following long term dehydration for your body to get used to being normally hydrated again and flush out the extra fluid it has been retaining.
Call your doctor immediately if you have pain, redness or heat in the swollen area, an open sore, shortness of breath or swelling of only one limb. If the swelling has never happened before and it persists for more than a couple days, call your doctor's office for advice.
Salt can increase the amount of fluid that you retain in your body.
When protein (especially albumin) levels in your blood go too low, the colloidal osmotic pressure will decrease and allow fluid to escape from blood vessels into your tissues, resulting in edema or swelling of the hands, feet, ankles, knees and/or belly.
Edema may be due to low levels of circulating proteins from poor protein digestion.
Ovarian function was investigated in 30 women with postural idiopathic edema by measuring plasma estradiol and progesterone levels between the 21st and 23rd days of the menstrual cycle. Plasma progesterone concentrations were found to be lower than 5ng/ml in 53% of the cases and lower than 10ng/ml in 83%. The ovarian dysfunction most frequently observed was inadequate corpus luteum, i.e. progesterone deficiency with normal plasma estradiol levels. In virtually all patients the initial disorder in capillary permeability, as evaluated by Landis' test, was fully corrected by progesterone administered orally. However, clinical improvement was less marked with treatments of short duration (2-3 consecutive cycles). In view of the complex cause of the disease, combined treatments in which progesterone might well play the major role are usually required. [Presse Med 1983 Dec 10;12(45): pp.2859-62 (translated)]
Hormones regulate the amount of interstitial fluid surrounding our body's cells. A hormone imbalance can result in too much interstitial fluid, and thus edema.
Semi-starvation can cause edema. People with eating disorders may interpret the puffiness of edema or any changes on the scale as weight gain or getting "fat" and may panic and purge or take laxatives even more.
There is no single, accepted gold standard treatment for idiopathic cyclic edema. Several different treatments have been reported. An agent used for treating high blood pressure called Captopril has also been used with success. It works against the kidney hormone aldosterone which is elevated in this condition and causes excess salt and water retention.
Sometimes a mild diuretic will help reduce fluid retention but can worsen the edema of idiopathic cyclic edema. While one would think that taking a "water pill" or diuretic would improve this edematous condition, it turns out that in most cases this is the wrong long term treatment. In fact, chronic diuretic use will increase the secretion of aldosterone which in turn produces more edema. If the chronic use of diuretics is discontinued, the cyclical swelling disappears in most cases within about 3 weeks.
Edema can be caused by a sedentary lifestyle – in other words, long periods of standing or sitting. If this is the case for you, regular exercise (not necessarily prolonged or strenuous) should help.
Food sensitivities should be ruled out in cases of edema of unknown cause. "I often recommend an empirical elimination diet in which common allergens (wheat, milk, eggs, corn, coffee, tea, alcohol, yeast, citrus and sugar) are removed for several weeks. Although edema is usually not their primary complaint, many patients report a pronounced diuresis and loss of edema fluid during the first several days of the diet. Foods that cause a return of a patient's presenting symptoms often cause fluid retention as well". [Gaby, AR. Idiopathic edema: Letter. Hospital Practice Feb. 15, 1986, p. 21]
Edema is a very reliable and accurate index in detecting a food reaction that may cause the body to suddenly retain as much as 4% of its body weight as edema fluid. This weight is gained within 6-8 hours of ingesting the guilty food and lost within 18-24 hours after the food has been removed from the diet. [Brenerman, JC. Basics of Food Allergy. Springfield, IL, Charles C. Thomas, 1978]
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