I've been so tired the past few weeks. my normal hr is 65-70. now it's been 47-50. is that abnormal? please help.

Good: Typically a lower heart rate signals better health. Runners and people who exercise regularly often have lower heart rates, where as people who are out of shape have higher heart rates. Some conditions can be associated with lower heart rate, for instance, hypothyroidism. If you're worried, get checked by your doctor and he/she can look for anemia as another reason for fatigue. Best of luck!

Bradycardia: Well trained athletes often have a slow heart rate, say less than 60 beats per minute. However, if your normal heart rate is higher, say 65-70bpm, then anything lower is abnormal, suggestive of damage to pacemaking portion of heart. In other words, you need to get evaluated immediately. Don't wait until you pass out!