Swollen ankles

Why are my ankles swollen at night?

By Healthy Legs Daily Editorial Team | Updated August 5, 2026

Ankles may look more swollen at night because fluid can collect in the lower legs after hours of sitting, standing, heat exposure, salty meals or limited movement. Sudden, painful, one-sided swelling or swelling with chest pain or shortness of breath needs urgent medical attention.

Common non-emergency reasons

• Long periods sitting at a desk, in a car or on a flight.
• Standing for many hours with limited calf movement.
• High-sodium meals that can affect fluid balance.
• Heat, alcohol, menstrual cycle changes or poor sleep.

What to try first

Gentle walking, calf raises, hydration, reducing high-sodium foods and elevating the legs may help some people. Compression socks may also help, but they should be selected carefully if you have circulation issues.

When to seek medical care

Get medical advice if swelling is new, severe, one-sided, painful, red, warm, worsening, or appears with shortness of breath, chest pain, faintness or coughing blood.