ZocdocAnswersWhy did my left ankle swell while I was asleep?

Question

Why did my left ankle swell while I was asleep?

I could barely walk

Answer

Swelling of the ankles is usually caused by an injury, such as twisting or spraining it. It would be pretty unusual to injure your ankle while sleeping. This makes me wonder whether or not you may have injured your ankle earlier during the day? If so, it could be that the inflammation and swelling was delayed enough that you went to bed without many symptoms but woke up with stiffness and swelling! Swelling in the ankles may also be a sign of a heart, kidney, or other serious medical problem. However, this almost always involves both ankles and doesn't usually develop out of the blue. Finally, the possibility of of a blood clot in one of the veins of the left leg - a deep venous thrombosis - needs to be considered, as this is the other potential cause of sudden and uncomfortable swelling of one leg. I recommend that you go see your primary care doctor about this as soon as possible. The can help you figure out what is going on with a physical exam, some blood tests and, potentially, an ultrasound of the leg looking for clots. In the meantime, if you have sudden chest pain or difficulty breathing, go to the emergency room as this might be a sign of a serious problem.

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