When Is Leg Swelling Cause for Concern?

When you sprain your ankle, twist your knee, or pull your hamstring, you expect to develop some degree of leg swelling as your body’s healing mechanisms spring into action. This typically acute (short-term) form of swelling results from inflammation and usually ends once your injury is on the mend. 

But what about swelling that appears in one or both legs in the absence of injury, maybe coming and going over time but generally persisting for no apparent reason? It’s likely a sign of fluid buildup, also known as edema.  

There are many reasons — ranging from no big deal to quite serious — that your lower legs, ankles, and feet might become swollen with fluid. Read on as our board-certified experts at Advanced Vascular Surgery explain when leg swelling is cause for concern.  

Leg swelling signs and severity

Lower extremity swelling is common, especially among older adults. Subtle signs of mild leg swelling include indentations on the skin when you remove your socks or skin that retains your fingermark for a few seconds after you gently press it. 

Moderate to severe leg swelling is much easier to spot: Your shoes may feel abnormally tight, your well-defined ankles may suddenly look like straight “cankles” (calf-ankles), or your skin may look significantly puffy, shiny, or stretched. 

Causes of fluid-related swelling 

Leg swelling that stems from injury and inflammation is usually painful. However, when fluid buildup (peripheral edema) is the underlying cause, leg swelling is typically painless. Lower extremity edema may be a temporary issue triggered by: 

• Standing mostly still (in place) for a very long time
• Sitting for long stretches (i.e., long-distance travel)
• Wearing tight-fitting stockings or pants for too long 

Lower extremity edema can be a persistent or recurrent problem, too: It’s a common side effect of pregnancy, obesity, chemotherapy, certain medications (i.e., hormone therapy), and even a sodium-rich diet. Chronic leg swelling may also be a “red flag” indication that there’s something seriously wrong, such as:

• Chronic kidney disease and/or acute kidney failure 
• Heart disease (heart failure, cardiomyopathy, pericarditis)
• Lymphedema, or a blockage in the lymphatic system 
• Thrombophlebitis, including deep vein thrombosis (DVT)
• Chronic venous insufficiency (CVI), or poor circulation 

Chronic leg swelling can also be a warning sign of pulmonary hypertension, which is high blood pressure that affects the artery leading from the lungs to the right side of the heart. 

When leg swelling is a concern

Noticeable lower extremity swelling that appears after a long-distance international flight or a day on your feet usually subsides within 24 hours, and isn’t cause for concern. 

When to seek an evaluation for leg swelling

If your leg swelling lasts more than a few days, frequently recurs after improving, affects just one leg, occurs around a varicose vein, or triggers leg pain, schedule an evaluation with our vascular experts as soon as possible.

When leg swelling requires emergency care

Leg swelling that’s accompanied by cramping, sharp pain, skin that’s red or warm to the touch, and swollen veins may indicate DVT, or a deep vein blood clot, that calls for prompt evaluation and treatment to guard against a life-threatening pulmonary embolism. 

Seek immediate emergency care if your leg swelling happens suddenly and for no obvious reason, especially if it’s only in one leg or it’s accompanied by:

• Chest pain and difficulty catching your breath
• Breathlessness during exertion or when lying down
• Sudden lightheadedness, dizziness, or fainting

Leg swelling is also a medical emergency if it’s accompanied by a sudden fever or a swollen abdomen, if you’re coughing up blood, or if it seems to advance and worsen quickly. 

Schedule a vascular ultrasound

Persistent or recurrent leg swelling — the kind that emerges gradually rather than suddenly, and isn’t accompanied by other worrying symptoms — isn’t typically a medical emergency, but it’s always cause for concern.  

Remember: Leg swelling that happens as a side effect of excess weight, a high-sodium diet, or taking certain prescription medications looks exactly like leg swelling that stems from a serious circulatory disorder or chronic illness. 

Prompt expert evaluation with an ICAVL-accredited vascular ultrasound is key to diagnosing the underlying problem so you can take steps to safeguard your health. 

Worried about leg swelling? We’re here to help. Schedule an evaluation at your nearest Advanced Vascular Surgery office in Kalamazoo, Allegan, Battle Creek, Coldwater, Sturgis, or Three Rivers, Michigan, today.