An Overview of Edema

Edema is the medical term used to describe swelling associated with injury, inflammation, or fluid overload. It can affect a small area, large area, or even the entire body. Edema is the result of the small blood vessels leaking fluid into tissues. When fluid builds up, tissue swells.

Symptoms

There are various different types of edema, and each has different health risks that go along with it. The symptoms of each type of edema are dependent upon the type, location, and cause.

Peripheral

Peripheral edema is the most common type of edema and affects the feet, ankles, legs, arms, wrists, and hands. Symptoms usually include increased swelling, puffiness, pain in muscle tissues and joints, and difficulty moving. Skin symptoms include pain, swelling, tightness, and a shiny, stretchy appearance.

Additional symptoms of peripheral edema include:

• Skin that retains a dimple when pressed for a few seconds (pitting)
• Puffiness in ankles, hands and/or face
• Joint aches and stiffness
• Full hand and neck veins

Macular

Macular edema involves swelling in the macula, the part of the eye responsible for detailed and centralized vision. This type of edema will change central vision and how colors are perceived. Macular edema is often a complication of diabetic retinopathy, an eye disease that affects people with diabetes. 

Early on, macular edema does not cause symptoms. When symptoms are present, it is an indication of blood vessel leakage. Symptoms include blurry and wavy central vision, colors that appear faded, and problems with reading any type of writing and viewing information on a computer screen. Left untreated, macular edema will eventually cause vision loss.

Pulmonary

Pulmonary edema causes excess fluid to build up in the heart and/or lungs causing breathing problems. Often it is caused by congestive heart failure or a lung injury. Pulmonary edema is a very serious condition and can be a medical emergency. Left untreated, it could lead to respiratory failure and/or death.

Symptoms of pulmonary edema include shortness of breath, difficulty breathing (especially when lying down), waking up breathless, chest pain, wheezing, excessive sweating, general body weakness and fatigue, and coughing up blood.

Cerebral

Cerebral edema happens in the brain for any number of reasons, many of which are life-threatening. Symptoms of edema in the brain include headache, neck pain and/or stiffness, vision loss (partial or whole), dizziness, nausea, and vomiting.

Symptoms of severe cerebral edema may include confusion, mood/mental state changes, memory loss, difficulty speaking and finding the right words, changes in consciousness, especially unconsciousness, physical weakness, incontinence, and seizures.

Be sure to make an appointment to see a healthcare provider for swelling, stretching, or pitting of skin.

Causes

There are many causes of edema. Causes are dependent on the type of edema.

Peripheral

Peripheral edema can result from sitting or standing in one place for too long. Fluid will get pulled into the legs and feet and cause swelling. In addition, other causes include medications (such as blood pressure drugs and pain medicines), too much salt in a person's diet, and low protein levels in the blood (often due to malnutrition).

Other causes of peripheral edema include:

• Venous insufficiency, a condition that causes edema when the valves of the legs become weakened. This makes it harder for the veins to push blood to the heart. It also leads to varicose veins and fluid in the legs. Venous insufficiency affects 30% of the population.
• Certain diseases such as conditions of the lung, liver, kidney, or thyroid, in which salt retention can occur.
• Joints that swell and retain fluid caused by an arthritis condition.
• Being pregnant, as it puts pressure on the blood vessels of the lower part of the body.

Macular

There are many different conditions and risk factors that may lead macular edema, including age-related eye conditions, such as macular degeneration and cataracts, which may cause macular swelling that leads to blood vessels leaking fluid in the retina. Certain medications might also cause macular edema.

For example, hydroxychloroquine (an antimalarial drug) and Tamoxifen (a breast cancer treatment) are two medications that may affect the retina, but there are many others. It is a good idea to check with your healthcare provider if any medications you are taking may affect your eye health, especially if you have other risk factors.

Other causes of macular edema include:

• Inherited and genetic disorders: Retinoschisis or retinitis pigmentosa are genetic conditions that cause problems with the retina resulting in central and peripheral (side) vision changes and loss.
• Inflammatory eye diseases: For example, uveitis—a condition that causes ongoing eye inflammation—can cause macular swelling.
• Eye tumors and eye injuries: Eye tumors (both benign and malignant) and eye injuries can lead to swelling of the macula.
• Diabetes: High sugar levels can damage blood vessels, which end up leaking in the macula.

Pulmonary

Pulmonary edema is often caused by a problem with the heart, usually in the left ventricle (one of the chambers) in the heart. Poor pumping of the left ventricle creates a buildup of fluid. Narrow arteries, heart valve problems, muscle damage, and high blood pressure can also weaken the left ventricle.

Respiratory problems, blood clots, inhaling toxins, and lung injuries can also lead to pulmonary edema.

Cerebral

Several factors can lead to brain swelling, with the most common being traumatic brain injuries, strokes, infections—both viral and bacterial, and brain tumors. Other causes include high altitude, drug use, carbon monoxide poisoning, and bites from poisonous animals (including reptiles).

Diagnosis

Diagnosing peripheral edema involves a simple physical exam. In peripheral edema, the skin of the swollen area is often stretched and shiny. Gently pushing on the swollen area for about 15 seconds will leave a dimple.

Other types of edema require a medical history, symptom history, and additional testing (such as blood work and imaging) in order for a healthcare provider to determine if someone has edema, the type of edema, and treatment options.

Treatment

The only way to treat edema is to treat the cause of it.

Peripheral

Healthcare providers may prescribe diuretic medications (water pills) to help push salt and extra fluid out of the body with urine output in peripheral edema.

Wearing supportive stockings can put pressure on legs to reduce fluid collection in the legs and ankles. Avoid standing or sitting for long periods. Lastly, reduce the amount of salt in your diet.

Macular

Treatment for macular edema depends on the severity of the condition and the health of the patient. Treatment may include ocular steroid and non-steroid anti-inflammatory eye drops, ocular steroid injections, anti-inflammatory medications to be taken orally, and/or surgery to remove excess fluid from the eye.

Most people will experience significant vision improvements with treatment.

Pulmonary

Pulmonary edema can be a life-threatening condition. Therefore, it requires prompt treatment. Oxygen therapy is usually the first treatment healthcare providers will use to manage symptoms, which may include a breathing tube or oxygen delivered through an oxygen mask.

Depending on the cause of pulmonary edema, additional treatments may be prescribed including medications to decrease fluid in the heart and lungs, to reduce blood pressure and control pulse, to take pressure off the heart, and/or to relieve anxiety and shortness of breath.

Cerebral

Treatment for brain swelling should be immediate as this is a life-threatening condition.

Treatment options include medications to reduce swelling and blood clots. Further treatment may include:

• osmotherapy, or the use of osmotically active substances (substances that reduce fluid) to shift excess fluid in the brain.
• hyperventilation to cause more exhaling and lower the amount of carbon dioxide in the bloodstream. Controlling carbon dioxide will lower blood flow and reduce pressure and swelling.
• hypothermia, which involves lowering body temperature to reduce swelling in the brain.
• ventriculostomy, a surgical procedure where a small incision is made in the skull to drain fluid from the brain.
• a surgery in which part of the skull is removed to reduce pressure and swelling in the brain.

Complications

Untreated edema can lead to complications. For peripheral edema, this includes stiffness and problems with walking, stretched and itchy skin, scarring between layers of tissue, and skin ulcers.

Among the complications of pulmonary edema is respiratory failure. Heart attack or stroke is a risk of both pulmonary and cerebral edema.

Cerebral edema could also lead to neurological issues, and vision loss could result from macular edema. Additionally, aside from the complications unique to certain types of edema, there are overlapping conditions that could occur as a result of every type of edema.

The best way to prevent complications is to treat underlying conditions appropriately to keep them from getting worse.

A Word From Verywell

Edema can be caused by a serious medical condition or something simple. Regardless of the cause, treatment can help to relieve swelling and prevent complications. It is a good idea to see a healthcare provider if you are unaware of the cause of edema or if there are symptoms more than just minor swelling and fluid buildup, especially if breathing or consciousness is affected or an injury has occurred.