Why Are My Legs Swollen? 6 Possible Circulation Problems

What Causes Leg Swelling?

Leg swelling, also known as oedema, occurs when excess fluid accumulates in the tissues of the legs or ankles.

This may happen when:

• Blood circulation slows down
• Veins are unable to return blood efficiently to the heart
• Fluid balance in the body is disrupted

Occasional mild swelling after long periods of sitting or standing can be normal. However, ongoing or unexplained swelling may indicate an underlying medical condition.

Several conditions affecting blood circulation or fluid balance can contribute to swelling in the legs.

1. Chronic Venous Insufficiency

Chronic venous insufficiency occurs when veins in the legs have difficulty returning blood back to the heart.

Healthy veins contain valves that help blood flow upward. When these valves become weakened, blood may pool in the legs, causing fluid to leak into surrounding tissues.

Common signs include:

• Swelling in the lower legs or ankles
• A feeling of heaviness in the legs
• Skin changes or darkening around the ankles
• Varicose veins

Symptoms often worsen after long periods of standing or sitting.

2. Deep Vein Thrombosis (DVT)

Deep Vein Thrombosis occurs when a blood clot forms in a deep vein, usually in the leg.

This can block blood flow and cause swelling in the affected limb.

Possible symptoms include:

• Sudden swelling in one leg
• Pain or tenderness in the calf
• Warmth in the affected area
• Skin redness or discoloration

DVT requires prompt medical attention because the clot can potentially travel to the lungs.

3. Heart Failure

When the heart cannot pump blood efficiently, fluid may build up in different parts of the body, including the legs.

This condition can lead to swelling in the lower limbs due to fluid retention and increased pressure in the veins.

Other symptoms may include:

• Shortness of breath
• Fatigue
• Rapid weight gain due to fluid retention
• Swelling in both legs or ankles

4. Kidney Disease

The kidneys help regulate the body’s fluid and salt balance. When kidney function is impaired, the body may retain excess fluid.

This can lead to swelling in areas such as:

• The legs
• The ankles
• The feet
• Around the eyes

Kidney-related swelling often occurs gradually.

5. Lymphoedema

Lymphoedema occurs when the lymphatic system is unable to drain fluid properly from tissues.

This leads to a build-up of lymph fluid, causing swelling that may affect one or both legs.

Characteristics of lymphoedema include:

• Persistent swelling in the limbs
• A feeling of tightness or heaviness
• Thickened or hardened skin over time
• Reduced flexibility in the affected limb

Unlike other types of swelling, lymphoedema may not improve significantly with simple rest.

6. Peripheral Artery Disease

Peripheral Artery Disease (PAD) occurs when arteries supplying blood to the legs become narrowed due to plaque build-up.

Although PAD more commonly causes leg pain during walking, it may sometimes contribute to swelling, especially when circulation is significantly reduced.

Other possible symptoms include:

• Leg pain or cramping during walking
• Coldness in the lower leg or foot
• Slow-healing wounds on the feet
• Changes in skin colour

PAD is an important sign of broader vascular disease.

Occasional mild swelling may not always indicate a serious problem. However, certain warning signs suggest that medical evaluation may be necessary.

Seek medical advice if you experience:

• Swelling that appears suddenly
• Swelling affecting only one leg
• Leg pain, redness or warmth
• Skin wounds that do not heal
• Persistent swelling that worsens over time
• Shortness of breath along with leg swelling

These symptoms may indicate an underlying circulation problem that requires medical attention.

Although not all causes of leg swelling can be prevented, certain habits can help support healthy blood flow and reduce fluid build-up.

Helpful habits include:

• Avoid sitting or standing in one position for long periods
• Take short walking breaks during long journeys
• Elevate your legs when resting
• Maintain a healthy weight
• Stay physically active
• Reduce excessive salt intake

These lifestyle measures may help reduce strain on the circulatory system.

Do Not Ignore Persistent Leg Swelling

Leg swelling is common, but it should not always be dismissed as a minor issue. In some cases, it may signal an underlying circulation or fluid balance problem.

Paying attention to symptoms such as persistent swelling, pain or skin changes can help ensure that potential vascular conditions are recognised early and managed appropriately.

Ref: F26