Tachypnea or tachypnoea is abnormally rapid breathing. In adult humans at rest, any respiratory rate between 12 and 20 breaths per minute is normal and tachypnea is indicated by a rate greater than 20 breaths per minute. Children have significantly higher resting ventilatory rates, which decline rapidly during the first three years of life and then steadily until around 18 years. Tachypnea can be an early medical sign of pneumonia in children.