What is swelling in the legs called? Understanding Edema and Its Causes

September 24, 2025 •

4 min read

The medical term for swelling in the legs, ankles, or feet is edema, or specifically peripheral edema. It occurs when excess fluid builds up in the body's tissues, and it's a condition experienced by millions of people. Understanding what is swelling in the legs called is the first step toward deciphering its potential causes and finding relief.

Quick Summary

The medical name for swelling in the legs is edema, which is the buildup of excess fluid in the tissues of the lower limbs. This condition, known as peripheral edema, can range from a temporary inconvenience to a symptom of a more serious underlying medical issue requiring professional attention.

Key Points

Edema: The medical term for swelling due to fluid buildup in body tissues is edema; in the legs, it's called peripheral edema.
Causes: Edema can result from sitting or standing too long, high salt intake, pregnancy, medication side effects, or more serious conditions like heart, kidney, or liver disease.
DVT Warning: Sudden, painful swelling in one leg could signal a deep vein thrombosis (DVT), a medical emergency requiring immediate attention.
Pitting vs. Non-Pitting: Pitting edema leaves a temporary dent when pressed, while non-pitting edema does not, helping to identify potential causes like venous insufficiency vs. lymphedema.
When to See a Doctor: Persistent or accompanied by other symptoms like pain, redness, or shortness of breath, leg swelling should prompt a medical evaluation.
Home Management: Mild edema can be managed by elevating the legs, exercising, reducing salt, and wearing compression socks.

The Medical Term: Edema and Peripheral Edema

Edema is the generalized term for swelling caused by fluid trapped within your body's tissues. When this fluid retention primarily affects the legs, feet, and ankles, it is known as peripheral edema. This condition can result from a number of factors, ranging from prolonged sitting or standing to more significant health concerns involving the heart, kidneys, or liver.

How Does Edema Happen?

Edema occurs because tiny blood vessels in the body, known as capillaries, leak fluid. This leakage can happen for several reasons, including increased pressure inside the vessels or a problem with the lymphatic system, which is responsible for draining excess fluid from tissues. When the fluid escapes, it pools in the surrounding tissue, causing it to swell.

Common Causes of Leg Swelling

There are numerous reasons why a person might experience leg swelling. The causes can be benign and temporary or indicative of a more serious, chronic condition.

Lifestyle Factors

Prolonged immobility: Sitting or standing in one position for an extended period, such as on a long flight, can cause fluid to accumulate in the legs due to gravity.
High salt intake: Consuming too much salt can lead to fluid retention in the body, contributing to edema.
Pregnancy: The increased fluid volume and pressure on the veins from the growing uterus can cause swelling in the legs and feet.
Obesity: Excess weight puts additional pressure on the veins in the legs and pelvis, which can hinder blood flow back to the heart and cause fluid buildup.

Underlying Medical Conditions

Chronic Venous Insufficiency (CVI): This condition occurs when the valves in the leg veins weaken and fail to efficiently pump blood back to the heart. This causes blood to pool in the lower extremities, leading to swelling and other symptoms.
Heart Failure: When the heart is too weak to pump blood effectively, it can lead to a backup of blood in the veins, causing fluid retention in the legs, feet, and abdomen.
Kidney Disease: Impaired kidney function can lead to an accumulation of excess salt and fluid in the body, resulting in swelling, often around the legs and eyes.
Liver Disease: Liver cirrhosis can cause changes in hormone production and blood flow, leading to fluid buildup in the legs (edema) and abdomen (ascites).
Deep Vein Thrombosis (DVT): This is a serious condition involving a blood clot in a deep leg vein, which can cause sudden, often unilateral, swelling and pain. DVT requires immediate medical attention.
Lymphedema: A blockage in the lymphatic system prevents proper drainage of lymph fluid, causing swelling in the limbs. It can be a complication of cancer treatment or a congenital condition.
Medications: Certain drugs, such as some blood pressure medications and non-steroidal anti-inflammatory drugs (NSAIDs), can have fluid retention as a side effect.

Pitting vs. Non-Pitting Edema

Not all types of edema are the same. A simple test can help determine the nature of the swelling.


Feature	Pitting Edema	Non-Pitting Edema
Appearance	Skin holds a dimple or “pit” when pressed firmly for a few seconds.	Skin appears tight and swollen but does not retain a dent when pressed.
Cause	Typically caused by systemic conditions like heart, kidney, or liver disease, or venous insufficiency.	Often associated with lymphedema or thyroid disorders, indicating thicker, protein-rich fluid.
Texture	Soft and doughy.	Firm and tense.
Underlying Issue	Caused by leakage of thin, watery fluid from capillaries.	Caused by buildup of protein-rich lymphatic fluid.

Diagnosis and Management

Because leg swelling can have many different causes, a proper diagnosis from a healthcare provider is essential. A doctor will typically perform a physical examination and may order tests like blood work, urinalysis, or imaging scans to identify the root cause.

Managing Edema at Home

For mild cases, particularly those caused by lifestyle factors, several at-home remedies can help alleviate symptoms:

Elevation: Raise your legs above your heart level for 30 minutes several times a day to help fluid drain away from your lower limbs.
Movement: Avoid sitting or standing still for too long. Moving and exercising your legs, especially during long trips, can prevent fluid accumulation.
Reduce salt intake: Limiting sodium in your diet can significantly decrease fluid retention.
Compression therapy: Wearing compression stockings can help prevent fluid buildup by gently squeezing the legs to improve blood flow.

When to See a Doctor

It is crucial to seek medical attention if you experience any of the following symptoms alongside leg swelling:

Sudden, significant swelling, especially if it affects only one leg.
Pain, redness, or warmth in the swollen leg, which could indicate a blood clot.
Shortness of breath or difficulty breathing, which could signal fluid in the lungs.
Chest pain or pressure.
Fever or infection in the swollen area.

Conclusion

Swelling in the legs, known medically as peripheral edema, is a common issue with a wide spectrum of potential causes. From simple lifestyle habits to complex underlying medical conditions, identifying the source is key to effective management. While mild cases can often be treated at home, persistent, painful, or sudden swelling warrants a professional medical evaluation. By understanding what is swelling in the legs called and what might be causing it, individuals can take proactive steps toward better health.

For more detailed information on specific causes like venous insufficiency, you can refer to authoritative sources such as the American Heart Association. For instance, see their educational content on understanding blood vessel conditions: American Heart Association.

Frequently Asked Questions

The main medical term for swelling in the legs is edema. When it specifically affects the lower limbs, including the ankles and feet, it is known as peripheral edema.

Yes, sitting or standing in one position for a prolonged period is a common cause of mild edema. Gravity causes fluid to accumulate in the legs, but it usually resolves with movement.

Not all leg swelling is serious. Mild cases from lifestyle factors are often temporary. However, sudden or persistent swelling can indicate a serious underlying condition and should be checked by a doctor.

Edema is a general term for fluid buildup. Lymphedema is a specific type of swelling caused by a blockage in the lymphatic system, which results in the accumulation of protein-rich lymph fluid.

Pitting edema is swelling that leaves a temporary indentation, or 'pit,' in the skin after being pressed. It's often associated with conditions like venous insufficiency or heart and kidney problems.

You should be concerned if swelling is sudden, affects only one leg, is painful, or is accompanied by chest pain or shortness of breath. These could be signs of a serious condition like a DVT or heart failure.

To reduce mild leg swelling at home, try elevating your legs above your heart, reducing your salt intake, staying active, and using compression stockings.