How can I stop my heart from racing?

Avoid stimulants/med. Can reduce risk of heart racing by avoiding caffeine/alcohol/stimulants. If it occurs vagal maneuvers (cold compress to forehead, light pressure on closed eyes, coughing, bearing down (valsalva). If recurrent episodes meds (beta blockers, calcium blockers) may be of help although additional structural information on heart (2d echo) can be helpful in deciding next steps.
Depends. What is your pulse? Do you drink caffeine, when do you feel the racing. See a doctor, get an ekg and thyroid test. Avoid etoh, caffeine and chocolates.

Related Questions

How can I stop my heart from racing after being scared?

Heart racing. Unfortunately you will have your heart racing after being scared - a big issue. I suggest you try and make an appointment to see a Psychologist. She/he will calm you down and give you excellent advice to get things under control. Please let me know how things go. Read more...
This is normal. Heart racing in the setting of fear is a normal response. You may be able to slow it down or blunt the intensity by vagal maneuvers, such as bearing down like you are having a bowel movement. Read more...
Sit down. When scared the heart races as a natural response. Sit down, and place your feet flat on the floor. Close your eyes and imaging watching a second hand on a clock in your mind. Breathe slowly and rhythmically. Your heart will gradually begin to slow down as you relax your mind. Measured breathing will also help. Also, say to yourself, I am calm and relaxed over and over. All should slow. Read more...