Edema

Edema is the swelling produced as a consequence of the accumulation of excess fluid in the tissues of the body. It is a symptom of numerous diseases that can occur in any part of the body.

Symptoms and Causes

Edema is the inflammation of soft tissues caused by the accumulation of fluid in the interstitial space, that is, in the space surrounding the cells that make up the body. It can occur in any part of the body, although it is more frequent in the lower extremities or in a generalized form.

Depending on its location, there are five types of edema:

Peripheral edema: it is one of the most frequent. Swelling occurs in the arms, hands, legs or feet.
Bone edema: fluid accumulates inside the bone, normally in the marrow.
Pulmonary edema: fluid accumulates in the alveoli, which are the small sacs in which the exchange of oxygen and carbon dioxide takes place. It is a medical emergency.
Cerebral edema: excess fluids accumulate in the brain, so intracranial pressure increases. It requires urgent medical intervention, as it may cause death.
Macular edema: it affects the macula of the retina, responsible for enabling central and detailed vision.

Mild and temporary accumulation of fluids in peripheral areas is harmless to the body, but when it is persistent and affects vital organs, it can pose a serious risk to the patient's health.

Symptoms

The main symptoms of the different types of edema are:

Peripheral edema: they usually increase at the end of the day.
- Evident swelling.
- The skin in the inflamed area appears tense and shiny.
- Pitting: in some cases, a depression appears in the skin after slight pressure.
- Sensation of heaviness and discomfort.
- Joint stiffness.
- Weight gain.
Bone edema:
- Intense and localized pain.
- Sensation of pressure in the bone.
- Difficulty moving.
Pulmonary edema:
- Dyspnea: difficulty breathing that worsens with exertion or when lying down.
- Sensation of suffocation.
- Cough that sometimes produces a foamy liquid.
- Respiratory sounds.
- Fast and irregular heart rate.
- Cold, moist, pale skin with cyanosis (bluish coloration).
- Sensation of anxiety.
Cerebral edema:
- Intense and persistent headache.
- Visual problems: double or blurred vision.
- Seizures.
- Nausea and projectile vomiting.
- Neck stiffness.
- Loss of consciousness.
- Drowsiness.
- Difficulty speaking or walking.
Macular edema:
- Blurred vision.
- Distorted vision: straight lines appear curved or twisted.
- Loss of central visual acuity: fine details are not perceived, making reading difficult, as well as the ability to recognize faces.
- Alteration of colors.
- Dark spots in the central visual field, peripheral vision remains unchanged.

Causes

Edema occurs when there is an imbalance between the forces that regulate the movement of fluids from one part of the body to another. This imbalance may be due to various factors:

Remaining seated or standing in the same position for a long time.
Excess consumption of salty foods and drinks.
Premenstrual syndrome.
Pregnancy.
Certain medications: nonsteroidal anti-inflammatory drugs, steroids, estrogens or those used to control hypertension or diabetes.
Congestive heart failure: the heart does not pump blood properly, so it may accumulate in some parts of the body.
Kidney disease: the kidneys do not eliminate excess mineral salts and fluid, so they accumulate in the body.
Renal damage: blood is not properly filtered and protein levels in the blood decrease, so pressure inside the vessels decreases and fluid leaks into surrounding tissues.
Hepatic damage: pressure in the veins increases and albumin production is reduced. As a consequence, the ability to retain fluids within the blood vessels is lost.
Venous insufficiency: the veins are weak and the valves that allow blood to flow in one direction are damaged, so blood accumulates.
Deep vein thrombosis: a blood clot forms in one of the veins of the legs.
Alterations in the lymphatic system: lymph is not properly drained and accumulates in the tissues.
Trauma or overload in the bones.
Osteoarthritis.

Risk factors

The risk of developing edema increases in the following cases:

Sex: women are more prone to peripheral edema, as there is a hormonal predisposition. It is more frequent during pregnancy, menarche (first menstruation) and menopause.
Following an unbalanced diet with excess salt.
Taking any of the medications indicated in the previous section.
Having any of the diseases described as a cause of edema.
Surgery on a lymph node.

Complications

The complications of edema can be mild or very severe. Some of the most frequent are:

Pain.
Stiffness.
Difficulty moving.
Skin problems: stretching of the skin, infections, itching, scar formation, development of ulcers.
Reduced blood flow.
Loss of elasticity in blood vessels, joints and muscles.
Permanent loss of central vision.
Respiratory failure.
Brain damage.
In very severe cases, death.

What doctor treats edema?

Depending on the type of edema, the specialties responsible for its treatment may include: Angiology and Vascular Surgery, Internal Medicine, Traumatology and Orthopedic Surgery, Pulmonology, Cardiology and Ophthalmology.

Diagnosis

The diagnosis of edema includes the following procedures:

Medical history: the specialist studies the patient's medical and family history, lifestyle and presenting symptoms.
Physical examination:
- The inflamed areas are observed and it is assessed whether they show pitting or whether the area is warm and painful.
- The general condition of the patient is assessed, such as skin color or amount of sweating. It is also monitored whether there are signs of anxiety.
- The lungs are auscultated looking for wheezing or crackles.
- The pulse is taken to determine whether tachycardia is present.
- It is observed whether there is periorbital hematoma (raccoon eyes), one of the signs of cerebral edema.
Neurological evaluation: it is carried out when cerebral edema is suspected:
- Glasgow test: evaluates the level of consciousness to detect whether there is brain damage.
- Cranial nerves: eye and facial movements, sensitivity and taste are assessed, among other aspects to diagnose cerebral edema.
- Pupils: dilation of the pupil or unequal size may be a sign of fluid accumulation in the brain.
- Blood and urine analysis to evaluate renal function and protein levels.
- Chest X-ray: provides images of the lungs in which diffuse opacities around the heart, thickening of blood vessels or pleural effusion can be detected as a sign of pulmonary edema.
- Electrocardiogram: provides information about the condition of the heart. Some conditions such as hypertrophy, myocardial infarction or ventricular overload may cause accumulation of fluid in the lungs.
- Brain computed tomography: provides detailed images of the brain that allow identification of the presence of accumulated fluid.
- Bone magnetic resonance imaging: images of the bones are obtained to observe fluid accumulation and inflammation.
- Vision test: necessary to diagnose macular edema. The Amsler grid allows detection of distorted lines.
- Optical coherence tomography: a beam of light is used to generate cross-sectional images of the internal structure of the eye. It is used to check whether there is fluid accumulation in the macula.

Treatment

Treatment varies depending on the type of edema present. The most frequent approaches are:

Peripheral edema:
- Rest with the limbs elevated.
- Mild exercise and avoiding prolonged sitting or standing.
- Use of compression stockings to mobilize fluid accumulation and promote venous return.
- Following a balanced, low-salt diet.
- Diuretic pharmacological treatment to eliminate excess fluid.
Bone edema:
- Rest.
- Physiotherapy: specific exercises and manual therapy to reduce fluid accumulation.
- Anti-inflammatory medication.
Pulmonary edema:
- Oxygen therapy: oxygen is provided artificially so that the body reaches the levels necessary to function properly.
- Artificial ventilation: positive pressure is used to facilitate air entry into the lungs.
- Medication: diuretics to eliminate fluids, vasodilators to ease cardiac workload, inotropes to increase heart pumping force.
Cerebral edema:
- Surgical drainage of accumulated cerebrospinal fluid.
- Decompressive craniotomy: an opening is created in the skull to relieve pressure.
- Farmacological treatment: osmotic agents to redirect accumulated water into the bloodstream, corticosteroids to reduce inflammation, diuretics to eliminate excess fluid.
Macular edema: vision loss cannot be repaired, but progression of damage can be prevented.
- Intravitreal injections of antiangiogenic agents to slow abnormal blood vessel formation and reduce edema.
- Corticosteroid infiltration to reduce inflammation.
- Laser photocoagulation to seal leaks from blood vessels.