What are the causes for dark purple spots in the arms, and how to manage them?

Hello,

Welcome to icliniq.com.

I have gone through your query carefully, and the photos you attached (attachments are hidden to protect the patient's identity), and here are my suggestions:

Those dark spots are indicating possible bleeding at that place, but it happened a few days back. Now, the blood has dissolved giving those dark purple spots. There are two possibilities:

1. You might have hit or gotten hurt at that place, for example, while lifting heavy weights.
2. Or you might have drawn blood at that place.

I do not see anything worrisome. Everything will be settled in a few more days, hopefully.

Let me know if you have any other concerns.

Kind regards.