Resting heart rate is the number of times your heart beats per minute when you are calm and at rest. For most adults this is 60 to 100 beats per minute. Well-trained athletes can have resting rates in the 40s or 50s, which is normal for them. A lower resting rate generally reflects better cardiovascular fitness.
Many things temporarily change heart rate, including caffeine, stress, fever, dehydration, pain and some medicines. Measure when you have been sitting quietly for a few minutes, for example first thing in the morning.
See a doctor if your resting rate is regularly above 100 or below 50 with symptoms such as breathlessness, dizziness, fainting or palpitations, or if your pulse feels irregular. A persistently irregular pulse can signal a rhythm problem like atrial fibrillation, which raises stroke risk and should be checked.