If your shoes feel tighter every summer, or your socks are leaving deep marks by the end of the day, you’re not imagining it. Swollen ankles and legs in hot weather are extremely common, especially for people over 60. Most of the time it’s simply how your body responds to heat — but it can occasionally be a sign of something that needs medical attention. Here are the three main reasons this happens, what actually helps, and the warning signs worth knowing. (Based on the insights of Dr. Suneel Dhand)
Key Takeaways
- Heat causes ankle and leg swelling through expanding blood vessels and reduced calf muscle pumping, especially with prolonged sitting.
- Moving at least once an hour and elevating your legs above heart level for short periods can meaningfully reduce swelling.
- Certain medical conditions and medications, including some blood pressure drugs, can also contribute to ankle swelling.
- Heat-related swelling is typically symmetrical (both legs), painless, and improves overnight.
- Swelling that’s painful, red, warm, one-sided, or paired with chest pain or shortness of breath needs prompt medical attention.
Reason #1: Your Blood Vessels Expand
Just like most things expand as they warm up, the veins in your legs widen in hot weather, which allows more fluid to leak into the surrounding tissue. Gravity makes this worse, since your feet and ankles are the lowest point of your body — which is why swelling tends to build throughout the day and is usually less noticeable first thing in the morning.
What helps: elevating your feet above heart level for short periods, even just 20 minutes at a time, can make a real difference when this is the underlying cause.
Reason #2: Your Calf Muscles Aren’t Pumping Enough
Your calf muscles work almost like a second heart — every step helps pump blood back up toward your heart. When you’re sitting for extended periods, whether it’s because it’s too hot to be active, you’re traveling, or just relaxing indoors, blood and fluid can start to pool around your ankles.
What helps: moving at least once an hour, even for just a few minutes. Walking, standing, rotating your ankles, or marching in place all help keep that pumping action going — even for people who find walking difficult, seated leg movements can help.
Reason #3: Underlying Medical Conditions
Sometimes it isn’t just the heat. Conditions such as heart failure, kidney disease, liver disease, poor circulation, and peripheral vascular disease can all exacerbate ankle swelling. Certain medications can contribute too — blood pressure medications like amlodipine (brand name Norvasc) are a commonly cited example. It’s worth not automatically assuming every swollen ankle is simply due to summer heat.
A Note on Electrolytes
Sweating more in hot weather means losing sodium along with other electrolytes like potassium and magnesium, which doesn’t help the situation. For most people with normally functioning kidneys, maintaining adequate salt intake in hot weather is actually important rather than something to restrict aggressively. That said, this is genuinely different for people with certain health conditions — anyone with kidney disease, heart failure, or a condition affecting sodium levels should follow their doctor’s specific guidance rather than general advice.