How Long Can Bad Air Quality Make You Sick?

Symptoms caused by poor air quality may last from a few hours to several days after exposure ends. Mild irritation—such as burning eyes, a scratchy throat, coughing, headache, or fatigue—often improves within 24 to 48 hours once you move indoors and breathe cleaner air.

Recovery can take longer after heavy or repeated exposure. Wildfire smoke, ozone, and fine particulate matter can continue aggravating the lungs for several days, especially in people with asthma, COPD, heart disease, or allergies.

The duration of illness depends on the pollutant level, exposure time, personal health, and whether clean indoor air is available. Children, older adults, pregnant people, and those with respiratory or cardiovascular conditions may experience stronger or longer-lasting effects.

Check the Air Quality Index before outdoor activities. An AQI above 100 can affect sensitive groups, while levels above 150 may cause symptoms in anyone.

Move to an indoor space with closed windows and filtered air. Run a properly sized air purifier with a true HEPA filter, set an HVAC system to recirculate, drink water, and avoid smoking, candles, frying, and strenuous exercise until symptoms improve.

After smoke exposure, changing clothes and showering can remove particles from the skin and hair. Learn more about how long bad air quality can make you sick and the factors that influence recovery.

Contact a healthcare professional if coughing, wheezing, chest tightness, or unusual fatigue persists for more than a few days. Seek urgent care for severe shortness of breath, chest pain, confusion, fainting, or blue lips or fingertips.

People with asthma should follow their prescribed action plan and use medications only as directed. Do not rely on an air purifier as a substitute for medical treatment.