When you are stressed by love, your body produces norepinephrine and adrenaline, the same chemicals that your body produces when you are threatened or in a crisis. These hormones can create a variety of physical symptoms, such as a fluttering sensation in your stomach. Your heart rate increases, too, because these hormones help you deal with danger. Stress caused by love causes your body to react in much the same way as if you were being threatened by violence or harm. Your brain sends signals to your organs, telling them to prepare for fight or flight. Your muscles tense up, your heart beats faster, and more energy is released from your stores into the blood stream. This increased activity helps you deal with threat which, at first glance, seems like a good idea but can also cause problems later on. The problem with stress caused by love is that it can lead to serious long-term health issues. If you worry about someone so much that it causes your body to be in a constant state of stress, then you are going to need to change something about your relationship. Worrying doesn't fix anything, and it's possible that you could end up with a whole host of medical problems down the road due to continual stress caused by love. The best thing you can do for your body when you are stressed by love is to take some time out.