Edema is a condition of increase in the internal fluid volume of the body. It increases several times before becoming apparent. It is manifested by swelling which may be localised over the affected part or generalised depending on the cause. 

Normally plasma volume inside the body is kept constant by various forces. Any disturbance in these forces can cause edema.

Generalised edema occurs because of disorders of the heart, liver, kidney, thyroid or protein deficiency.

Fluid can collect in the lungs, which can be fatal if untreated. The earliest symptom is breathlessness on exertion and as it progresses patient is forced to sit up at night because lying down aggravates the condition. This can occur because of heart failure. It may occur as part of generalised edema.

Long standing hypertension, abnormalities of the heart valves, ischemic heart disease, chronic lung diseases and infections of the heart, among others, precipitate right ventricular failure leading to edema. The swelling appears on the legs after exertion or in the evenings. There is indentation of the skin of the ankle while pressing, which is characteristic. In later stages swelling also occurs over the face and abdomen.

In case of chronic kidney disease, edema first appears on the face and that too in the morning. Along with it the sufferer would have urinary symptoms like frequency and urgency of urination. Later on it also becomes generalised.

Similarly, protein deficiency also leads to facial edema in the early stages followed by generalised edema.

Cirrhosis of the liver is the commonest liver disorder leading to generalized edema. The main feature of it is predominant collection of fluid in the abdomen known as ascites.

In bed ridden persons, irrespective of the underlying cause, swelling develops over the sacral region and feet.

Various conditions produce localised collection of fluid . Tumors or infections of the peritoneal cavity like cancer or tuberculosis cause ascites.

Edema of only one or two legs is seen with filariasis, HIV infection, infections of the veins or lymph vessels.

Varicose veins a condition of dilatation of the veins of lower limbs is also associated with edema.

Chronic persistent infections of the skin cause localised edema in the affected part. Insect bite or localised allergy causes small swelling over the affected part.

Women of menopausal age tend to develop edema on the feet and face because of the hormonal influence.

Diagnosis of the cause of edema is important for treatment. It is done by the history, clinical examination, and relevant tests for a suspected condition.

Generalised edema should not be taken lightly. Something seemingly trivial may progress to something irreversible. Once the functioning of any vital part of the body is deranged, it is irreparable. Hence if diagnosed early, the condition producing edema can be controlled very well.

Salt restriction is useful to manage edema. Diuretic drugs i.e. drugs which promote mobilisation of extra fluid from the body are used in all cases of generalised edema. When taken for long, at times the edema tends to become refractory, necessitating increase of dose. The risk of side effects like electrolyte imbalance, muscle cramps and tinnitus is also increased. Thus a vicious cycle is established where one cannot do without the diuretic and when taken side effects are produced. Bed rest reduces the metabolism of the body. This provides rest to the affected part by reducing work load on it and helps reducing breathlessness due to edema.

The specific treatment is treatment of the underlying cause. Therefore, it is advisable that if edema is noticed anywhere, it should not be neglected.

Dr. Rachna Pande is a specialist in internal medicine at Ruhengeri Hospital