Types of Edema

Edema is the medical term for the buildup of excess fluids in the body’s tissues. This occurs when the body fails to excrete excess fluid through kidneys or skin. 

The formation of edema is controlled by the balance of a number of forces. The two most important forces involved are hydrostatic pressure and oncotic pressure.

Hydrostatic pressure is the pressure generated by fluids while oncotic pressure is the osmotic pressure generated by proteins in blood plasma.

The accumulation of fluid or the formation of edema is, therefore, controlled by the following factors:

• Rising hydrostatic pressure
• Falling oncotic pressure in the blood vessels
• Rising oncotic pressure in the tissues
• Degradation of the walls of blood vessels which leads to increased permeability reduced oncotic pressure and leakage of fluids
• Impairment of the lymphatic system which is responsible for clearing fluids from interstitial spaces
• Increasingly hydrophilic (water-loving property) nature of tissues.

Edemas can also be classified by the organ or system which is affected. Some of these types of edemas can also be further subdivided. 

Some of the common causes of edema may be trauma, a change in your body’s chemical composition, allergy, or other factors. 

There are different types of edema. Some of them are specific to certain parts of the body, while others may be more generalized. 

Generalized Edema 

Generalized edema is a condition when you notice swelling, puffiness, and water retention in various body parts, including your abdomen, arms, legs, face, and feet. 

Symptoms include bloating, tightening of skin, and skin that holds an imprint or looks pitted. This type of edema may be caused by trauma, illness, pregnancy, or chemical imbalance in the body. 

Pitting Edema is a severe case of edema which exists if the skin retains an indentation after being pressed for 10 to 20 seconds. 

Skin Edema 

Skin edema mainly occurs in the tissues and cells of the skin. It is usually harmless, but it can be very painful. In this type of edema, some parts of your skin may seem tight, puffy, and have fluid retention. 

You may experience skin edema after having a surface allergic reaction caused by mosquito bites, detergents, chemicals, or other irritants. Skin edema is also referred to as cutaneous. 

Periorbital edema is also related to skin edemas.

It is also called eye puffiness and it is the temporary accumulation of fluids in the periorbital tissues surrounding the eyes. It is believed to be caused by gravitational pull on fluids when lying horizontally.

Peripheral Edema

Peripheral edema mainly occurs in the legs, feet, and ankles. This is the most common type of edema and it causes swelling in the lower extremities. 

This type of edema may be caused by increasing age, pregnancy, hypertension, congestive heart failure, kidney problems or other health conditions. 

You also may experience peripheral edema if you have been sitting or standing for extended hours. Some medications may also cause peripheral edema:

• Calcium channel blockers
• Pramipexole
• NSAIDs (ibuprofen, naproxen)
• Pioglitazone and rosiglitazone
• Corticosteroids (prednisone, methylprednisolone)

Corneal Edema 

When there is water retention in the cornea, it causes corneal swelling, which is an eye problem known as corneal edema. 

This type of edema is caused by dehydration, endothelial disorder, ocular surgery, viral infections, traumatic injury, increased ocular pressure, and toxins. 

Cerebral Edema

In cerebral edema, fluids accumulate in the intracellular and extracellular spaces of the brain. It can be caused by metabolic abnormalities due to an underlying disease or as a response to oxygen deprivation at high altitudes.

Cerebral edema is a very serious form of edema. It can lead to loss of consciousness and brain damage.

Cerebral edema can be further divided into four subtypes of edema. These are vasogenic, cytotoxic, osmotic and interstitial cerebral edemas.

Vasogenic cerebral edema occurs when the blood-brain barrier breaks down. This allows plasma to leak into the brain, first reaching the white matter before getting to the grey matter. This type of cerebral edema is caused by tumor, trauma and cardiovascular events.

When cancer is involved, vasogenic edema is often caused by the release of destructive compounds from the tumor to compromise the integrity of the blood-brain barrier.

Vasogenic edema can also be subdivided by causative agents. Some of the types of vasogenic edemas are hydrostatic cerebral edema (caused by acute hypertension), cerebral edema from brain cancer (caused by cancerous glial cells of the brain) and high altitude cerebral edema (which can be worsened by high altitude pulmonary edema).

Cytotoxic cerebral edema is caused by the malfunctioning of the sodium and potassium pump of the glial cells. This leads to the accumulation of sodium and water and then the swelling of the gray and white matter. The blood-brain barrier is unaffected in cytotoxic edema.

Osmotic cerebral edema occurs when the brain osmolality exceeds the plasma osmolality.  The pressure generated drives fluids into the brain to cause edema.

Interstitial edema occurs when the barrier between the brain and the cerebrospinal fluid ruptures. This causes the inflow of cerebrospinal fluid into the brain and its accumulation in the white matter and extracellular spaces.

Pulmonary Edema

Pulmonary edema is the accumulation of fluids in the lungs due to the blockage of the pulmonary veins. As blood pressure rises in the blood vessels of the lungs, fluids rush in to fill the lungs.

The pleural cavity can also be filled with fluid. In such cases, the pulmonary edema is said to also present with pleural effusion.

Pulmonary edema is usually caused by the malfunctioning of the left ventricle of the heart. It can also be triggered by inhaling harmful air-borne toxins and also by high altitudes.

Myxedema

Myxedema is a rare form of edema. It occurs when the connective tissues are filled with water-loving carbohydrate-like compounds such as hyaluronan. These compounds attract water into the tissue matrix and swell up quickly.

It is believed that myxedema is also worsened because the transfer of fluids in the tissues to the lymphatic system is also hampered. Myxedema is common in the elderly especially when they sit for prolonged periods of time.

Lymphedema

Lymphedema is caused by the failure of the lymphatic system to remove fluids from the interstitial spaces.

This form of edema can be caused by a number of things. Notably, it can result from enlarged lymph nodes, cancer, destruction of the lymph vessels by radiation therapy, infection of the lymphatic system, and inhibition of the pumping actions of the lymph hearts by certain medications such as ibuprofen.

What Are The Treatment Options? 

The treatment mainly depends on the type of edema. Most health care providers will recommend you to follow a low-sodium diet and take the prescribed diuretics. You may also try some home remedies such as: 

• Regular exercise
• Reduce salt consumption
• Elevate legs while sleeping
• Avoid standing or sitting for extended hours
• Lose weight if required
• Wear support stockings
• Limit your alcohol, sugar, caffeine intake
• Avoid salty food

You may try alternative remedies such as acupuncture, oxygen therapy, and massage therapy. You may also consider taking Capisette, a natural fluid retention remedy which contains powerful ingredients such as dandelion extract, horse chestnut, ginkgo biloba, and buchu.