A respiratory rate of less than 12 breaths per minute is known as bradypnea. This is associated with a low metabolic rate, drug overdose, shock and increased intracranial pressure. A respiratory rate of more than 24 breaths per minute (tachypnea) is associated with pneumonia, pulmonary embolism, pleurisy, bronchial asthma, congestive heart failure, hypermetabolism and anxiety.