Acute respiratory distress syndrome (ARDS) A condition that happens when fluid builds up in the lungs, causing blood oxygen levels to drop below normal and oftentimes deadly levels. ARDS results from lung damage due to trauma or illnesses such as COVID-19.

Asymptomatic Having no signs of a disease. The term asymptomatic can be used to describe:

• Someone who’s infected with a virus or other pathogen and can spread a disease, but doesn’t have symptoms themselves
• Someone who’s carrying a disease, but isn’t yet showing symptoms
• Or, someone without symptoms who doesn’t have a disease. 

Contact tracing The process of identifying people who have an infectious disease and anyone they have recently been around — and then alerting those individuals so they can either isolate or get tested — to help prevent the disease spread. 

Community spread The spread of a disease between people in the same geographical area that cannot be linked to a known source.

Coronavirus The term for a family of viruses that can cause illness in humans and animals, which can be mild, like the common cold, or more severe, like Middle East respiratory syndrome (MERS) and COVID-19.

COVID-19 The name commonly used to refer to the disease caused by the novel coronavirus, SARS-CoV2 (severe acute respiratory syndrome coronavirus.) COVID-19 is short for “coronavirus disease 2019.”

Flattening the curve Slowing the rate at which people are becoming infected with a disease. A slower rate of new cases can help avoid overwhelming hospitals and health care providers.

Herd immunity When risk of infection in a given group or population is reduced because a high percentage of those individuals have already been infected and developed immunity — and are thus unable to catch the illness.

Immunocompromised When the body’s ability to fight off germs and infection is weakened because of a preexisting health condition or medication. 

Incubation period The time between when a person is exposed to a virus or other pathogen and when symptoms start to appear.

Isolation Separating people who are sick from people who are not sick to prevent the spread of infectious disease.

N95 A type of face mask designed to fit snugly to protect the wearer from airborne germs and particles like smoke, dust, or fumes. N95 masks also protect others from germs or liquids the wearer may expel. Surgical N95s are a subset of N95 Filtering Facepiece Respirators (often just referred to as N95s) that are cleared by the U.S. Food and Drug Administration for use as surgical masks for health care providers. N95s are considered “respirators” (see below), which require training for proper use according to the U.S. Centers for Disease Control and Prevention. 

Personal Protective Equipment or PPE Equipment worn by workers to minimize exposure to workplace hazards. In this case of COVID-19, PPE typically refers to respirators and other face coverings, gloves, gowns and goggles to reduce health care workers’ exposure to the coronavirus. 

Pre-symptomatic When someone is carrying a disease, but is not yet showing symptoms. Note: Pre-symptomatic individuals will eventually develop signs of a disease while asymptomatic individuals will not.