Swelling in Leg and Its 5 Causes
- Dr Tan Yih Kai
- August 4, 2021

What are the causes of swelling in leg?
Leg swelling is a common condition. It is referring to excessive buildup of fluid in the leg. Both men and women of all ages are equally affected. It can occur in one or both legs depending on the cause. There are many reasons why legs can be swollen. It is crucial to find out the causes as some of them may be serious and life-threatening.
The common causes of leg swelling include the following:
1. Venous insufficiency
Venous insufficiency is a very common cause of leg swelling. Failure of valves (Varicose veins) or damage of valves (from previous deep vein thrombosis (DVT)) in the leg veins will prevent the blood in the veins from travelling back towards the heart effectively. This results in pooling of blood in the veins of the affected leg and hence fluid buildup in the tissue.
2. Heart failure
Failure of heart to pump blood out effectively to all the organs can lead to backlog of blood pooling in the legs and hence buildup of fluid.
3. Kidney failure
Kidney failure will lead to reduced function in filtering wastes and excreting excess fluids from the body. Swelling or fluid retention tend to affect both lower limbs and it may affect arms in more severe cases.
4. Pregnancy
Leg swelling is a normal part of pregnancy. Third trimester, starting from week 28, is the most common period to experience it. This is because the growing baby in the uterus can cause external compression to the pelvic veins, which are major veins that allow blood to return to the heart. However, leg swelling during pregnancy may be a sign of more sinister problem. For example:
- Preeclampsia especially if it is also associated with severe headaches, vision problems and nausea/vomiting
- DVT especially when it is associated with redness and pain in the calf
5. Medications that cause leg swelling
It is important to check the list of medications that you consume as some of them may be associated with leg swelling. For example:
- NSAIDs (Non-steroidal anti-inflammatory drugs) such as Ibuprofen and Voltaren are commonly used to manage pain and inflammation. They are known to be one of the causes because of their salt retention property.
- Oral steroids such as prednisolone are commonly used for severe asthma, severe allergies and autoimmune diseases like rheumatoid arthritis. Leg swelling can occur because of salt retention too especially in prolonged usage.
- High blood pressure medications – medication like amlodipine is known to cause the leg to swell. Do seek help from your doctor to check through your list of medications and modify them as necessary.