The normal number of breaths varies among different age groups. Adults breathe 16-20 times per minute, newborns breathe up to 40-60 times per minute, and children breathe up to 20-30 times per minute. 1. Adults: 16-20 breaths per minute. The ratio of respiration to pulse is 1:4, which usually means that for every breath, the pulse beats 4 times. Generally, women will be 1~2 times faster than men, which is also a normal phenomenon. 2. Newborns: The respiratory rate can be as high as 40 to 60 times per minute. 3. Children: Children will breathe faster than adults, up to about 20-30 times per minute. It is important to note that if there is a slowing down of the respiratory rate, it may be related to overdose of anesthesia and significant increase in intracranial pressure. If there is an increase in the number of breaths, it may be related to fever, pain, anemia, bronchial asthma and other disease factors, so it is important to pay attention.