After a stretch of cooler weather and showers, Santa Ana winds are expected to return to San Diego County on Thursday.

For people with allergies and asthma, the effects can start as soon as they step outside, said Dr. Amy Zheng, an urgent care physician at Sharp Rees-Stealy.

“Unfortunately, with the winds, it picks up a lot of particles in the air, moves it around, we breathe in these particles,” Zheng said. “They go into our noses, they go into our lungs, they go into our eyes.”

Zheng is an allergy sufferer herself, and knows what it’s like to deal with them.

“They make our eyes itchy, scratchy, gritty, our noses are runny, dry. And then that leads to, then, overproduction of mucus, because your body's trying to compensate for it,” she said. “You may end up with some post-nasal drip, and then it go into coughing fits.”

People should pay attention to air-quality alerts before heading outside, she said.

“If you have asthma, if you've got lung disease, if you know you have nasal issues, then try to avoid going out when the apps give you a warning or an alert,” she said. “At least think twice about it. Do you really have to go out now?”

She recommends keeping windows closed and staying hydrated.

“Our body needs that in order to fight anything that we have going on in our bodies, to keep our mucous membranes, our eyes, our mouth. Our noses, keep them moist, and if you can do that, then the body will have less of a chance to overreact,” she said.

For some people, Zheng said taking additional steps to manage symptoms may be necessary.

“We can certainly take a look and see if you need some changes in your medication,” she said. “At least briefly while this is going on, and then, you know, once it's over, you can go back to your usual maintenance dose.”

Zheng also cautions that not every respiratory symptom should be attributed to allergies, particularly as cold and flu season gets underway.

“If you're short of breath, if you're having lung issues, breathing issues, if your heart rate's going fast, if you have body aches, that's not normal for allergies,” she said.

Those symptoms should be evaluated by a healthcare professional, she said.

The effects of changing environmental conditions on health are an area doctors are continuing to study.

“Doctors are recognizing the effect of climate change on people's health. And it's incredible. I mean, we're seeing it every day, right?” Zheng said.