What could possibly be wrong with my leg/ankle--I've had edema for about 4 years, now pain?

You could possibly have a DVT in your left ankle. DVT stands for Deep Venous Thrombosis. This clot could have broken off, and lodged further up in the vein. With that being said, the signs and syptoms of that would be localized pain and swelling, that you are presenting with. If that vein is blocked, then you will have venous stasis, "impared blood flow" in the lower left extremety. This will cause blood to pool into the sight of question, and cause pitting edema which you have described. It could be due to an initial injury maybe that you sustained 4 years ago, and exacerbated by the skiiing. Your doctor should perform a venous dopler exam in order to diagnose this. In the mean time you could take aspirin 81 mg, 2 tablets every morning, depending on your age. This will help from platelet aggregation to the thrombosed sight, and help prevent further thrombotic activity to your leg. Only take the aspirin if you are over 18 though, due to risk of Reye's Syndrome. Aspirin at this dosage prevents certain inflammatory chemicals, (i.e prostaglandin's and thromboxane) from working properly to allow platelets to clot together. Your body has a natural anti platelet agent in it that inhibits platelet's from aggregating "sticking together", and it is called prostacycline, or PCI when your Dr. abbreviates it. That natural bodily chemical isn't effected by the aspirin at the dose of 81 mg to 162 mg, but if you dose above 325 mg, then the aspirin starts inhibiting prostacycline, which negates the effect you are needing. The only way that the aspirin will have an advrese event in you is, if you are under 18 and are running a fever, or you have an active gastric or duodenal ulcer, or history of ulcers or GI bleeding. The aspirin might upset your stomach, so take it with food or milk, and that will take care of the upset stomach effect. Good luck, I hope the Dr has good news, and a firm diagnosis for you. He/She should run a set of labs on you during your visit, such as a CMP "comprehensive metabolic profile", a coagulation and hematology panel "this measures hemoglobin, hematocrit, and mean cell volume, as well as your total platelet count. Hope all this information has been of some help to you, and hope that your Dr. can come to a conclusive diagnosis, and start a treatment plan that will treat the problem, and help alleviate your pain and normalize your life. Best of luck to you!!!