Edema or swelling is a symptom that is commonly known as swelling because it is when there is “swelling” or “water pooling” in a certain area or part of the body. If it is due to inflammation, it is accompanied by redness and pain.

What is swelling? What are the main causes of edema?

Swelling occurs when excess fluid in blood and lymph “leaks” from a vessel (blood vessel – capillary or lymph) and accumulates between cells. Depending on its composition, we call it an exudate or an exudate. A correctcapillaryhas awall built in such a way that it resembles a very fine strainerwhich allows fluid to pass in both directions (from tissue to vessel and from vessel to tissues) – in this way, under normal conditions, oxygen and nutrients are distributed from the blood to the cells, and waste products and carbon dioxide are reabsorbed. This flow normally remains in a certain equilibrium (i.e. the same amount of fluid seeps from and into the vessel so that it does not accumulate in the tissues) because it is regulated by several factors, including proper structure and operation of the vessel wall, pressure inside and outside the vessel, the presence of appropriate proportions of proteins and electrolytes inside the vessels and in the tissues (the so-called oncotic and osmotic pressure). If too much fluid builds up outside the vessel, swelling develops. This can happen when:

1. the permeability of the vessel wall increases (e.g.in inflammationorallergies) – then the vessel wall is affected by substances that damage it, and the vessel expands, making the “strainer mesh” larger and the liquid easier to get outside;
2. pressure increases in a part of the vessel due to the presence of an obstruction that obstructs blood flow in the vessel (e.g.in thrombosis, prolonged pressure from the outside), so that more fluid is forced out of the vessel through the wall;
3. the flow in the vessel slows down, and the pressure inside the entire vessel increases dueto heart failureorvenous insufficiency,
4. the fluid itself is “diluted”, i.e. its composition is incorrect, poor in proteins (i.e. low oncotic pressure) and / or with abnormal electrolyte concentration (i.e. low osmotic pressure) – e.g. in certainliver and kidney diseasesormalnutrition,anorexia.

How does the doctor make the diagnosis when edema occurs?

Swelling is a symptom that can be caused by many different things. Most of them can be determined by the doctor after talking with the patient and examining the swollen area. Any swelling that has no obvious cause and lasts longer than 2-3 weeks should be consulted with a doctor!

If the swelling is small and covers a small area of ​​the skin or a single part of the body, it is calledlocal swelling. Local swelling may result from:

1. allergic reaction– such swelling is often accompanied by itching and a small rash that appears and disappears quite quickly (hives);
2. inflammatory reaction– such swelling is red, warm and painful. It can occur after aninjury, around thewound, in places of insectbites , sunburns, and in some autoimmune diseases (such asrheumatoid arthritis);
3. venous insufficiency– such swellings result from regurgitation of blood and obstructed flow in insufficient, dilated veins. Most often, in such a situation, the swelling is greatest in the evening, after long standing, and disappears after a night, accompanied by dilated superficial veins of the lower limbs (varicose veins);
4. thrombosis– most often there is thrombosis of the superficial veins of the lower extremities (varicose veins), which is not life-threatening. However, the so-calleddeep vein thrombosisof the lower limbs (venous thromboembolism), which is a serious hazard and you should contact your doctor immediately if you suspect it (see symptoms below);
5. obstructed outflow of lymph – this can happen if the flow through the vessels is obstructed by a tumor ( cancer ) or adhesions (after surgery or radiation or chemotherapy). Certain rare infectious diseases also cause it;
6. Angioedema: This is a sudden, often unclear, local swelling around e.g. the face, without redness, rash or pain that comes and goes. It can be caused by an inherited genetic defect or by taking certain medications.

A special situation of local edema is the swelling of the entire organ. As already mentioned, the swollen organ stops working properly. Edema can therefore be life-threatening if it concerns an organ essential for life. Examples of such situations arepulmonaryedema and cerebral edema.Laryngeal edema, which in extreme cases can cause suffocation, is also dangerous .

If the swelling affects the entire body it is calledgeneralized swelling. Since generalized swelling is a build-up of fluid outside the vessels throughout the body, it is accompanied by weight gain. Generalized edema may result from:

1. heart failurea – it causes stagnation in the entire circulatory system. Soft-to-touch swellings with a trace of pressure (so-called pasty) are usually most visible on the lower limbs or – in people lying down – around the sacrum. If a person with circulatory insufficiency has increased arterial pressure, fatigue, weight gain and swelling of the legs develop, the current treatment is most likely insufficient – see a doctor;
2. liver failure– may be accompanied byascites, i.e. the accumulation of fluid in the abdominal cavity and the widening of the veins on the skin of the abdomen;
3. nephrotic syndrome– this is a kidney disease in which massive swelling of the entire body gradually appears;
4. hormonal disorders– most often inhypothyroidism. The swelling, typical of hypothyroidism (although not always present), affects the face and eyelids. Other symptoms of hypothyroidism include sudden weight gain, extreme drowsiness, a slower reaction, and freezing easily;
5. malnutrition– occur in extreme cases of anorexia and in people with severe gastrointestinal diseases and after other severe, debilitating diseases;
6. pregnancy;
7. drug-induced – most often it concerns long-term treatment with glucocorticosteroids (commonly steroids).

Can swelling be dangerous?

In exceptional circumstances, swelling can be a dangerous signal and you should consult your doctor immediately. The following situations should be of concern:

1. Swelling(sometimes only a thickening of the circumference!)Affecting only one of the lower limbs, often the calf, sometimes accompanied by pain. These could be signs of a deep vein thrombosis;
2. Increasing swelling around a wound or abrasion, painful and red. Thewoundoften oozes whitish content. Wound infection may be suspected, especially urgent intervention is required when it is accompanied byfever;
3. Excessive swelling after insect bites. The following are especially dangerous:
   • a bite insidethe mouth and throat(laryngeal edema is life-threatening),
   • a bitein a person allergicto insect venom (most often bees and wasps),
   • swelling far from the site of the sting, feeling hot, short ofbreathand suddenly feeling unwell.
4. Swelling accompanied by skin changes(reddening of the skin, i.e. erythema, rash, papules, local subcutaneous nodules and tissue induration) – may indicate an autoimmune disease beginning;
5. The appearance of a significant and painfulswelling after trauma to a given area(usually a limb) may indicate abrokenbone or joint damage.
6. Swelling around the face, mouth, neck– this may be a sudden allergic edema (e.g. caused by eating something that someone is allergic to, such as peanuts) or angioedema, and swelling rapidly increasing caused by diseases with blockage of the superior jugular vein – significant swelling of these areas, especially the swelling that increases quickly, makes breathing and swallowing difficult, is dangerous to health and life and requires an immediate emergency (tel.999or112 )). However, less sudden and smaller swellings also require medical attention – often less swelling of the face (especially lips, cheeks) can accompany serious infections around the teeth, including abscesses that are dangerous to health and must be urgently treated (dental emergency).