My physiotherapist says it's fine to have blood pressure taken on my lymphedema arm and also a blood test. However best not to have an intravenous line in the affected arm, though if it was to save my life, it would be worth taking the risk. I currently wear a sleeve and have a bracelet on the other arm to say no blood pressure etc on my affected arm. I have one which is silver metal with stretchy links so it is easy to put on and off. I thought it was important to get one and wear it, but am not so certain now. I have one where the company has details of my allergies to medications. I suppose it might help one day. The trouble is, if the bracelet is unobtrusive it might not get noticed but I don't want to wear daily something that isn't unobtrusive!