What Are the Causes of Leg Swelling Below the Knee?

Leg swelling can be a seriously debilitating condition that interferes with one's ability to perform even the most basic daily tasks. If left untreated, it can worsen over time. Swelling below the knee can be linked to various underlying diseases, some of which are mild, while others can be life-threatening. Recognizing the causes and knowing when to seek medical attention are crucial steps in managing this condition.

If you're noticing extra pressure, swelling, or heaviness in your lower legs, this article is for you. Understanding the causes of leg swelling below the knee and recognizing the symptoms that require medical attention can help you manage your health more effectively. 
 

When Should I See a Doctor for Swelling Below the Knee?

Swelling below the knee can sometimes signify a more serious health issue. See a doctor immediately if you experience difficulty breathing, chest congestion, fever, dizziness, or persistent swelling that doesn’t improve within a few days. These symptoms may indicate a severe condition that requires prompt medical attention, such as a vascular issue or heart failure.

Swelling that persists for several days or worsens can indicate an underlying medical condition that must be addressed. If left untreated, the condition causing the swelling could progress, leading to more severe health problems. Therefore, timely medical intervention is crucial to avoid potential complications.

What are Common Causes of Leg Swelling Below the Knee?

Leg swelling usually occurs due to fluid retention or inflammation. In most cases, swelling results from fluid accumulation in the legs, known medically as peripheral edema. This condition is often a symptom of underlying health issues, some related to vascular health, while others may involve the heart, kidneys, or other systems.

Is Swelling Below the Knee a Vascular Issue?

Swelling below the knee can often be related to vascular issues. Peripheral edema, for instance, involves excessive fluid buildup in the legs and is frequently seen in individuals over 50. This condition is often a symptom of underlying vascular problems ranging from mild to severe.

Deep Vein Thrombosis

One of the most common vascular issues associated with leg swelling is Deep Vein Thrombosis (DVT). DVT is a condition where blood clots form in the deep veins of the legs, usually in the calf. Swelling below the knee, accompanied by pain and redness, is a common symptom. DVT is a serious condition because the blood clots can break loose and travel to the lungs, causing a potentially life-threatening condition known as a pulmonary embolism. Obesity and a sedentary lifestyle can increase the risk of DVT, making it essential to seek medical care if you notice these symptoms. Treatment typically involves anticoagulant therapy to prevent further clotting.

May-Thurner Syndrome

May-Thurner Syndrome can also cause leg swelling below the knee. This condition occurs when the iliac vein is compressed, disrupting blood flow from the legs to the heart. Patients with May-Thurner syndrome often experience leg swelling, which worsens with activity. Although this condition is relatively rare, it can lead to significant discomfort and complications if not properly managed. Diagnosis often involves imaging studies, and treatment may include procedures to relieve the vein compression.

Heart Failure

Heart failure is another significant cause of leg swelling related to vascular issues. In advanced stages of heart failure, the heart struggles to pump blood effectively, leading to fluid buildup in the lower extremities. Studies show that a significant percentage of heart failure patients present with lower leg swelling, often accompanied by other symptoms like shortness of breath, fatigue, and chest pain. Heart failure-related edema typically occurs because the weakened heart causes blood to back up in the veins, leading to fluid leakage into surrounding tissues. This condition requires careful management under the guidance of a healthcare provider, as untreated heart failure can lead to severe health complications.

Lymphedema

Lymphedema, for example, is a condition that involves the leakage of lymph fluid into the legs, leading to swelling. Lymph is a protein-rich fluid that circulates in the lymphatic system, part of the immune system. When there is an abnormality in the lymphatic system, such as a blockage or damage to the lymph vessels, lymph fluid can accumulate in the tissues, causing swelling. Various factors, including cancer, cancer treatments, infections, and congenital conditions, can trigger lymphedema. The swelling caused by lymphedema typically worsens over time and can become quite severe if not properly managed. Treatment may involve compression therapy, manual lymph drainage, and, in some cases, surgery.

Varicose Veins

Varicose veins and chronic venous insufficiency are other common causes of swelling in the lower legs. Varicose veins occur when the veins near the skin's surface become twisted, enlarged, and inflamed. This can cause blood to pool in the legs, leading to swelling, aching, and discomfort. Venous insufficiency, on the other hand, occurs when the veins cannot return blood to the heart effectively, causing blood to pool in the legs and leading to chronic swelling. These conditions are more common in individuals with long-standing periods, such as nurses, teachers, and retail workers. Treatment for varicose veins and venous insufficiency may include lifestyle changes, such as increasing physical activity, wearing compression stockings, and avoiding prolonged standing. Medical procedures such as sclerotherapy, laser treatment, or vein surgery may be necessary in more severe cases.

Other more benign causes for swelling below the knee include but are not limited to:

• Injury or trauma to the legs
• Insect bites or stings
• Overexertion
• Heat
• Prolonged standing or sitting
• A high-sodium diet 
• Pregnancy
• Medication side effects

Talk to your primary care provider or vascular specialist if you’re experiencing any unexplained swelling below the knee.
What Happens If I Don’t See a Doctor for Swelling Below the Knee?
Ignoring leg swelling below the knee can lead to severe complications. Conditions like DVT can result in life-threatening situations if untreated, as blood clots can travel to the lungs, causing a pulmonary embolism. Similarly, untreated heart failure can progress, leading to severe health consequences such as worsening shortness of breath, severe fatigue, and even sudden death due to heart failure. Kidney disease can also progress, leading to more extensive fluid retention, high blood pressure, and ultimately, kidney failure requiring dialysis or a kidney transplant.

If the swelling is related to an underlying vascular condition, such as chronic venous insufficiency or May-Thurner syndrome, failing to seek treatment can lead to chronic pain, increased risk of infections, and long-term damage to the veins. If left unmanaged, these conditions can significantly impact quality of life and require more intensive treatment.

Can I Improve My Vascular Health to Prevent Swelling Below the Knee?

Improving vascular health is crucial for preventing and managing leg swelling. Several strategies can help reduce the risk of developing vascular issues and improve overall leg health. Regular physical activity, such as walking, swimming, and cycling, can improve blood circulation and help prevent conditions like DVT and chronic venous insufficiency. These activities can also strengthen leg muscles and improve blood flow, reducing the risk of swelling.

Maintaining a healthy weight is also essential for vascular health. Excess weight can put extra pressure on the veins and increase the risk of conditions like varicose veins and venous insufficiency. Eating a balanced diet rich in fruits, vegetables, whole grains, and lean proteins can support overall health and prevent weight gain. 

Elevating your legs whenever possible can also help reduce swelling. Keeping the legs elevated above the level of the heart can help move excess fluid back toward the heart and reduce the risk of fluid buildup in the lower legs. This can be particularly helpful after long periods of standing or during pregnancy.

Wearing compression stockings can prevent fluid buildup in the legs and reduce the risk of swelling. Compression stockings apply consistent pressure to the legs, helping to improve blood flow and reduce the risk of blood pooling in the veins. They are handy for individuals who spend long periods standing or sitting, as well as those with a history of venous insufficiency or DVT.

Another simple way to reduce swelling is to elevate your legs whenever possible. Elevating the legs above the heart level can encourage fluid return to the heart and reduce the risk of fluid buildup in the lower legs. This can be particularly beneficial after long periods of standing or during pregnancy. 

Talk to your vascular specialist before embarking on any new exercise diet or taking any new over-the-counter medications if they are not suitable for you.

Vascular Health and Wellness at Center for Vascular Medicine

Leg swelling below the knee can be a symptom of various underlying conditions, some mild and others life-threatening. Understanding the potential causes and knowing when to seek medical attention is crucial for managing your health. While mild swelling may not be a significant cause for concern, a healthcare provider should evaluate persistent or severe swelling to determine the underlying cause and appropriate treatment.

Improving vascular health, maintaining a healthy weight, and following preventive measures can help reduce the risk of developing leg swelling and improve overall leg health. If you notice ongoing leg swelling or other concerning symptoms, consult a healthcare provider to determine the best course of action.  You can book an appointment with a Center for Vascular Medicine online, call (301) 486-4690, or find a Center for Vascular Medicine location near you.