<s>[INST] I have constant pain in my left foot, on the outer left side between my toes and my ankle. Compared to my right foot, looking at it, it looks a little swollen, although there is no redness. Even when I go to bed to sleep for the night, the pain is always there, even laying down. What could it be? [/INST] Dear Patient, Single join tie ankle of one side getting involved, swelling but no redness, indicate towards an arthritic joint, you need to screen this and help your doctor find out the cause of this arthritis, You fail to provide some information like your age, since when are your symptoms, also do you feel any stiffness in the ankle or other joints on getting up in the morning. Just see your doctor and discuss your concern. Thanks </s>