It's surprising how even your arms swell and can become painful when you are inappropriately or excessively dosed with Premarin or other oestrogen-containing drugs, including some birth control meds or HRT.
Read of my own experience in this matter and of how I found a simple drug-free way to lessen the harm done. It's best to avoid pharmaceutical drugs if you possibly can. Just because they are prescribed for you, it doesn't mean that they are safe. Your doctor may not be well-informed about their side-effects, and the drug companies are notorious for down-playing harmful effects or keeping them secret for as long as they can. Big Pharma is/are frequently in the criminal courts for this and other misdemeanours. See this page also - especially if you did not know that oestrogen is a steroid.