tachypnea

Tachypnea is an abnormally rapid breathing rate, defined clinically as a higher-than-normal respiratory rate for a person’s age. In adults, a respiratory rate above the upper limit of normal—often cited as more than about 20 breaths per minute—constitutes tachypnea. In children the threshold varies with age, making clinical context essential.

Tachypnea is a sign rather than a diagnosis. It can reflect respiratory, metabolic, infectious, cardiovascular, or neurologic problems, and may occur with fever, pain, anxiety, or altitude. Common causes include acute infections such as pneumonia or bronchiolitis, asthma or COPD exacerbations, pulmonary edema or embolism, congestive heart failure, and metabolic acidosis (for example diabetic ketoacidosis). Less urgent causes include fever, anxiety, pain, or post-anesthesia recovery. In newborns and young children, tachypnea can be an early sign of lower respiratory tract infection.

Pathophysiology: Tachypnea arises from increased ventilatory demand or reduced lung compliance, prompting the respiratory centers to drive a faster rate to maintain oxygen delivery and carbon dioxide removal. Some patterns, such as Kussmaul breathing, accompany metabolic acidosis and feature a deep and labored regular rhythm rather than mere rapid shallow breaths.

Evaluation and management: Assessment includes careful measurement of respiratory rate, observation of work of breathing, oxygen saturation, and vital signs. Arterial blood gas and chest imaging may be indicated to assess gas exchange and lung pathology. Management targets the underlying cause and may include supplemental oxygen for hypoxemia, bronchodilators for airway disease, antibiotics for infection, fluids or insulin for metabolic derangements, and, in severe cases, ventilatory support. Persistent tachypnea with signs of respiratory distress requires urgent evaluation.