The volume of body fluids represents 60 to 70% of a young thin individual’s weight. In elderly obese, the volume is smaller: 50 to 60%. The fluids are distributed in 40% inside the cell (intracellular) and 20% outside the cell (extracellular). Of the 20% that are outside the cell, 5% occur in the vessels (intravascular) and 15% are in the interstice (interstitial fluid is the one situated between the tissues). This way, a healthy man weighing 70 kg has about 42 liters of body water; 28 liters are inside the cells, and of the remaining 14 liters, 3,5 liters remain in circulation and 10,5 liters remain between the tissues.
Our organism has several very sensitive sensors that regulate the volume, composition and pressure of fluids. If required, in order to regulate the inner environment, they increase or decrease the secretion of regulating hormones.
What is it?
Edema is an abnormal buildup of fluid in the interstitial space. It is constituted of a watery solution salts and proteins in the plasma, which exact composition varies according to the cause of the edema. When the fluid accumulates throughout the body, it is called general edema, while when it occurs in certain areas it is called localized edema, such as edema in person's legs with varicose veins.
|Types of Edema|
|There are three types of edema: commun edema, lymphedema and the myxedema|
|It is made up of water and salt, almost always generalized.|
Edema resulting from the accumulation of lymph. It occurs in cases in which lymphatic vessels are obstructed or have been ablated, as in the removal of ganglia in the course of breast cancer surgery. Ganglion excision facilitates the appearance of the edema in the arm. Another example of lymphedema is elephantiasis, which is accompanied by gross deformaty of the lower limbs. Myxedema
It is another type of edema with special features: hard and with an opaque skin aspect, occurring in the cases of hypothyroidism. In the myxedema, in addition to water and salts, there is an accumulation of special proteins produced by hypothyroidism.
What does it look like?
There two forms of edema: localized and generalized. When generalized
Lymphedema and myxedema are localized forms. Commun edema can be of two forms. When it is generalized, it spreads throughout the body, especially the limbs, face and hands. Generalized edema can occur inside the abdomen (ascites) and inside the lungs (pulmonary edema or pleural effusion).
Any type of edema, regardeless of its localization, causes a decrease in the speed of blood flow and impairs, by means of this mechanic device (pressure), the nourishment and efficiency of tissues.
Clinically, edema can be a sign of cardiac, hepatic, renal, severe malnutrition, hypothyroidism or venous or lymphatic obstruction, condition. These diseases trigger various alterations that result in edema. Each one having its own characteristics and the individuals affected having specific complaints.
In heart failure conditions, in addition to shortness of breath, edema starts in the lower limbs and can extend to the lungs (pulmonary edema) and abdomen (ascites). In the cardiac disease, it caused by the lack of strength of the heart to make the blood circulate.
In hepatic conditions and malnutrition, the cause is the lack of plama albumin. Albumin keeps the fluids in circulation. When albumin decreases, below 2,5g% in the blood, it can no longer keep the water inside the vessels, causing it to spread across the tissues.
In renal conditions, edema is due to water and salt retention that are eliminated conveniently.
In the venous and lymphatic obstruction, the blood and lymph have difficulties circulating, and collect in the tissues
In hypothyroidism, in addition to water and salt retention, there is a protein associated infiltrating the tissues (myxedema).
A very particular edema
There is a very particular, often found, common edema – the idopathic edema. While it has been extensively investigated, its origins is not yet known. It occurs in young women aged 20 to 50 years old. As a rule, these women make use and abuse of diuretics or cathartics for constipation. They are virtually always on a slimming diet, with low salt and diuretics. It an edema appearing rapidly in the limbs and face without an apparent cause, and can affect the whole body. Today, it is believed that the cause of this edema of unknown cause may be due to one or more factors:
Mineralocorticoid hormone secretion, which retain water and salt Plasma albumin decrease due to inadequate diet Local circulatory factors with altered capillaries standing for long periods ( orthostatism) Malfunction of the venous and lymphatic return Psychological alterations having impacted on the woman's hormone activity.
There are some drugs that may cause edema: antidepressants, antihypertensives (beta-blockers, clonidine, amlopidine, others), hormones (corticoids, estrogen, progesterone, testosterone), non-steroids antiinflammatory drugs, as well as the chronic use of diuretics (habit) and cathartics.
Cada uma dessas causas de edema requer tratamento específico, portanto não há um só tipo de tratamento. Each of these causes of edema requires specific treatment and, therefore, there is not only one type of treatment.