Accumulation of fluids in body may result from various medical conditions such as congestive heart failure, hypertension, varicose veins, and thrombophlebitis and by pregnancy in some women. Such accumulation is called edema and can also be caused by nutrient deficiency in some people.
Mechanism Behind Occurrence Of Edema
Edema can be caused by increase in pressure of blood against the walls of blood vessels. The proteins present in blood offers some pressure on the plasma of blood vessels, which causes pulling of water into the blood circulation from the tissues. Reduction of this pressure can cause accumulation of water. Certain inflammation responses in the body and problems with clearance of fluids by lymphatic system might also lead to accumulation of fluids.
Edema Can Affect Different Organs Of The Body
Most common form of edema is pulmonary edema. Removal of blood through pulmonary vein can be hindered either by failure of left ventricle of heart, hypoxia in high altitudes or through toxic chemical compounds inhaled. Such hindrance results in increased pressure in the blood vessels of lungs resulting in pulmonary edema. Altitude sickness leads to reduced oxygen supply and thereby abnormal metabolism of brain tissues leading to accumulation of fluids; the condition being referred cerebral edema. Insect bites or allergens can cause increased water retention and swelling of skin called cutaneous edema. Any obstruction to the lymph nodes can prevent proper lymphatic drainage and could cause lymphedema. Conjunctivitis of the eyes, surgery or glaucoma can cause edema in the cornea of eyes. During the second and third trimesters of pregnancy fluid retention might occur in the lower limbs of women.
Treatment Options Available For Edema
An important factor for treating edema is to understand the underlying cause correctly. When edema is found to have occurred from pressurization in specific body parts such as limbs or feet, the pressure can be relieved by positioning the legs in order to remove the pressure. This method can also be used when edema is known to have resulted from obstruction to veins. Sometimes edema may be caused by use of certain medications and can be relieved by stopping that medicine. Another common way to treat edema is to take diuretics so that the excess fluid accumulated in body may be removed in form of urine.
How Do Diuretics Help In Reducing Edema?
Diuretics such as furosemide inhibit the re absorption of sodium and chloride ions in the ascending limb of nephrons in kidney. By inhibiting this reabsorption, a hypertonic environment is created in the renal medulla region. Because of this, water does not achieve enough osmotic potential to leave the collecting duct and hence there is increased synthesis of urine. Also, furosemide leads to dilation of blood vessels by synthesis of compounds called prostaglandins and increase the blood delivery to kidney. If administered orally, the diuresis starts within one hour and might last up to eight hours. If administered as injection, diuresis will start within five minutes and could prolong for two hours.