I just had radiation (metastatic breast cancer) i was told i most likely have anemia from it. my resting heart rate is 102. is this from the anemia? what can i do?

Yes, resting heart rate above 100 is abnormal and one of the causes is moderate to severe anemia (Hb less than 10). However, many other conditions can also cause tachycardia such as radiation induced inflammation. You need a physical exam and a basic blood test. The treatment, if needed, should be coordinated by your primary care doctor and the radiation oncologist.

Anemia is likely multifactorial and an isolated heart rate of 102/min is hard to interpret as it is borderline high with a variety of possible causes, including anemia. There is nothing specific you need to do as the heart rate is reactive.