Methamphetamine can cause strain on your heart, you can also become so tensed up that pulling a muscle becomes easier. Sometimes muscles you didn't know you even have. If you start to have numbness on one side of your body or your heart beat becomes very heightened ( more than normal for amphetamine use) I would recommend going to urgent care or the ER where they can give you a sedative. Meth and amphetamine use can do damage to your heart that does not always go away so use it wisely and in moderation. ODs from meth are somewhat rare in relation to other drugs but can and do happen, usually due to heart problems. I also recommend getting a BP monitor if you feel your heart rate is too high. My .02$