How is ecchymosis diagnosed?

Your doctor will examine the affected areas and ask you when you started to feel your symptoms. Tell him if you had a recent trauma or if you have a medical condition that can cause the condition. Tell him about all the medications you take and if you notice any symptoms after taking a medication.
The doctor will take note of the important elements (personal history, family history, diet, etc.). He will also be interested in dental extractions: if they are always followed by a major hemorrhage. In this case, this is no doubt a problem of coagulation.
You may need blood tests to measure the amount of inflammation. The tests may also show signs of infection or they may test how your blood is clotting. If necessary, he will investigate further and may require vitamin dosing, bone marrow puncture and some other tests.