What is edema and where does the excess fluid come from?
To understand the swelling of the feet and legs, known as edema, it is essential to know where this excess fluid comes from. There are two main sources: plasma from your circulatory system and lymphatic fluid from your lymphatic system.
Plasma is the liquid part of your blood. In some cases, it can leak through the walls of your blood vessels and become trapped in your lower limbs due to gravity. Lymphatic fluid contains white blood cells and can accumulate in your feet and legs when your lymph nodes are damaged or blocked.
Common causes of edema in the feet and legs
Certain lifestyle factors can be major culprits, such as standing or sitting for too long, which increases pressure on your veins. A diet high in processed foods can also promote inflammation. Weight gain, excessive consumption of sugar, salt, and vegetable oil, as well as nutritional deficiencies, can all contribute to this problem.
Being overweight or obese increases pressure on your veins, leading to fluid retention. During pregnancy, hormonal changes and increased blood volume can also cause fluid retention. As you age, the valves in the veins of your legs can weaken, allowing blood and fluid to pool in your legs instead of flowing back to your heart.
Main health conditions causing swelling of the feet and legs
Lymphedema
This refers to chronic swelling of the arms or legs caused by the accumulation of protein-rich fluid. Lymphedema can develop if lymph nodes are removed or damaged during cancer treatment, radiation therapy, infections, or when obesity blocks fluid flow.
High blood pressure
When high blood pressure is not controlled, it can damage the valves in the veins of your legs, causing venous insufficiency or leaking veins. This leads to blood and fluid retention in the legs.
Heart failure
Prolonged high blood pressure forces the heart muscle to compensate by thickening. When this fails, it leads to heart failure, where blood flows backward in the veins, increasing pressure and causing fluid to leak into the legs, ankles, and feet.
