Ankle swelling can be caused by a variety of factors, some of which are more concerning than others. Here are some possible causes of ankle swelling:

• Injury: An injury to the foot or ankle can lead to swelling. The most common is a sprained ankle, which occurs when an injury or misstep causes the ligaments that hold the ankle in place to be stretched beyond their normal range. To reduce the swelling from a foot or ankle injury, rest to avoid walking on the injured ankle or foot, use ice packs, wrap the foot or ankle with compression bandage, and elevate the foot on a stool or pillow.

• Venous insufficiency: Swelling of the ankles and feet is often an early symptom of venous insufficiency, a condition in which blood inadequately moves up the veins from the legs and feet up to the heart. Normally, the veins keep blood flowing upward with one-way valves. When these valves become damaged or weakened, the blood leaks back down the vessels and fluid is retained in the soft tissue of the lower legs, especially the ankles and feet.

• Heart, liver, or kidney disease: Sometimes swelling can indicate a problem such as heart, liver, or kidney disease. Ankles that swell in the evening could be a sign of retaining salt and water because of right-sided heart failure. Swollen legs may be a sign of heart failure, kidney failure, or liver failure. In these conditions, there is too much fluid in the body, and it collects in the legs and feet.

• Warm temperatures: Another cause of ankle swelling is warm temperatures. The small blood vessels in the skin dilate to allow heat to escape, which helps keep body temperature from rising. But this also means more than the usual amount of fluid can leak into the surrounding tissues, especially in the legs. You can help prevent ankle swelling in warm weather by reducing your salt intake, which decreases fluid retention, and by staying hydrated.

• Medications: Certain medications may also cause your legs to swell. Some of these are antidepressants, blood pressure medicines called calcium channel blockers, hormones such as estrogen (in birth control pills or hormone replacement therapy) and testosterone, and steroids.

If you experience ankle swelling, it is important to consult your primary-care doctor if the issue persists or is accompanied by other symptoms.