Pulse rate depends a lot on the health, age and activity level of a person but usually a low pulse rate is the sign of a healthy heart, with many athletes having resting pulse rates in the 40 to 60 (beats per minute) range. Sometimes however, a slow heart rate/pulse, known medically as bradycardia, can be a sign of an underlying health problem, especially if coupled with tiredness, weakness and fainting. In cases like this, it is always wise to check with your doctor.
The beat in your veins that you feel at various places on the body, (the wrist is an example), is a way of measuring heart rate. Heart rate is the number of times a person’s heart beats per minute and is an indicator of how hard the heart is working.
A resting heart rate anywhere in the range of 60 - 90 is considered normal but children and babies can have faster pulses. Heart rates will fluctuate a lot, depending on factors such as activity level, as well as emotions and body weight - if you’re angry, stressed out or upset, your pulse rate is likely to be much higher than if you are calm, for example.
There are a number of medical conditions that can cause the pulse to be slow and these include malnutrition and a thyroid gland that is not functioning properly (hypothyroidism).
If you want more information on this topic, The National Emergency Medicine Association (NEMA) has a webpage with a lot of interesting detail on it.
If you are at all concerned about your pulse rate, it is best to consult your doctor, pharmacist or nurse who can use a blood pressure monitor to establish your pulse rate and rule out any possible underlying health problems you might have.