Final answer:
The term for difficulty breathing unless upright is orthopnea, which is distinct from dyspnea on exertion, apnea, and hypoxia. Identifying this condition helps in diagnosing and treating respiratory diseases.
Step-by-step explanation:
The term that means it is difficult for a patient to breathe unless he or she is in an upright position is orthopnea. This is often observed in patients with heart failure, respiratory disorders, or certain neuromuscular conditions. It contrasts with conditions like dyspnea on exertion, which refers to difficulty breathing upon physical activity, or apnea, which is a temporary cessation of breathing during sleep. Hypoxia represents a condition of insufficient oxygen in the tissues, which can be related to respiratory issues but does not specifically describe difficulty in breathing based on body position. Understanding these differences is important in the medical field for the accurate diagnosis and treatment of respiratory ailments.