2 doctors weighed in:

Why does my heart beat speed up and slow down?

2 doctors weighed in
Dr. Cory Annis
Internal Medicine & Pediatrics
1 doctor agrees

In brief: It depends

Heart rate varies naturally with your breath.
In some folks, it's really obvious & called "sinus arrhythmia" which is not harmful. With that, your pulse consistently slows when you breathe in and speeds up when you breath out. However, there is such a thing as "too fast" usually over 100 at rest, and "too slow", usually under 50 at rest. See your md if you are not sure.

In brief: It depends

Heart rate varies naturally with your breath.
In some folks, it's really obvious & called "sinus arrhythmia" which is not harmful. With that, your pulse consistently slows when you breathe in and speeds up when you breath out. However, there is such a thing as "too fast" usually over 100 at rest, and "too slow", usually under 50 at rest. See your md if you are not sure.
Dr. Cory Annis
Dr. Cory Annis
Thank
Get help from a real doctor now
Dr. Tonga Nfor
Board Certified, Internal Medicine - Cardiology
13 years in practice
508K people helped
Continue
111,000 doctors available
Read more answers from doctors