I gave a deep tissue electric neck and back massager to my 29 year old daughter for Christmas. I had noticed when I purchased the gift that one of the reviewers mentioned that her cardiologist had told her to stop using the massager immediately after she noticed the directions suggested those with a history of blood clots not use the device. At the insistence of her siblings, I allowed my 16 year old, 100 pound daughter with a mechanical mitral valve to use the massager for just a few minutes. She said it felt wonderful, but immediately afterwards, she had two huge red bruises precisely where the massaging balls had rested on her neck. It looked like we had punched her. I'm just curious--has anyone on warfarin ever noticed excessive bruising after using an electric massager or after having a professional massage? My daughter said the massager was incredibly relaxing, but obviously, I won't allow her to use it again.