What condition is characterized by a reduced supply of oxygen to the tissues?

Hypoxia is characterized by a reduced supply of oxygen to the tissues. It occurs when there is an insufficient amount of oxygen available for cellular metabolism, leading to a potential failure of normal physiological function. This can happen due to various reasons, such as impaired respiratory function, reduced oxygen availability in the environment, or problems with hemoglobin's ability to carry oxygen. The tissues begin to suffer, which can manifest in symptoms like confusion, lethargy, or cyanosis, depending on the severity and duration of the hypoxic condition.

Hyperoxia, on the other hand, refers to an excess of oxygen in the tissues, which is the opposite of hypoxia. Dyspnea is the term used for difficulty breathing, and while it can occur with hypoxia, it does not specifically denote reduced oxygen supply to tissues. Apnea refers to a temporary cessation of breathing and is also distinct from the concept of tissues being deprived of oxygen.