Which process does the body use to protect itself from disease?

Tachycardia refers to an abnormally fast heart rate, which can occur due to various factors such as stress, anxiety, or heart conditions. While it may be a physiological response to stress or infection, it does not directly protect the body from disease but rather indicates an underlying condition that may need attention.

Hypoxemia is a medical condition characterized by low levels of oxygen in the blood. This condition can lead to various health issues and does not play a role in the body's defense against disease. Instead, it poses a risk to overall health and may exacerbate existing medical conditions.

Syncope, or fainting, occurs when there is a temporary loss of consciousness, often due to a drop in blood flow to the brain. While it can be triggered by various factors, including stress or dehydration, it is not a protective mechanism against disease, but rather a symptom that may indicate other health issues.