Senior citizens are among the most vulnerable to the deadly COVID-19 contagion. But as more and more cases have emerged, doctors have learned that coronavirus symptoms in seniors look very different than they do in other patients. In a report from Kaiser Health News, Camille Vaughan, MD, section chief of geriatrics and gerontology at Emory University, said, "With a lot of conditions, older adults don't present in a typical way, and we're seeing that with COVID-19 as well."

The reason why coronavirus symptoms are different for senior citizens has to do with how aging bodies respond to illness and infection. Joseph Ouslander, MD, professor of geriatric medicine at Florida Atlantic University, told Kaiser Health that, at advanced ages, "someone's immune response may be blunted and their ability to regulate temperature may be altered." He added that "some older people, whether from age-related changes or previous neurologic issues such as a stroke, may have altered cough reflexes. Others with cognitive impairment may not be able to communicate their symptoms."

To learn more about how coronavirus symptoms differ in seniors, read on.

1 They seem "off."

Cognitive impairment is one atypical symptom of COVID-19 in the elderly. "Someone may be just having a bad day," Vaughan said. "But if they're not themselves for a couple of days, absolutely reach out to a primary care doctor or a local health system hotline to see if they meet the threshold for [coronavirus] testing." And for more on how to get tested, check out Here's How to Find COVID-19 Testing Options Near You.

2 They're sleeping more than usual.

Stay-at-home orders and self-quarantine has likely led to a surge in nationwide naps. But if your elderly friend or family member is sleeping more than usual, that could be an atypical symptom of the coronavirus. According to Kaiser Health, Sylvain Nguyen, a geriatrician at the University of Lausanne Hospital Center in Switzerland, conducted research on the COVID-19 symptoms in older patients for an upcoming paper in the Revue Médicale Suisse. Nguyen lists both fatigue and lethargy among the symptoms.

3 They have no appetite.

Severe loss of appetite is another symptom of coronavirus in seniors, according to Nguyen's research. To make matters worse, the lack of protein and fuel weakens their already compromised immune system. And for tips on how to improve immune health, check out 10 Tips for How to Boost Your Immune System.

4 They're apathetic or depressed.

Isolated seniors may "become apathetic or depressed" due to coronavirus, according to the Kaiser Health report, which can be exacerbated by "not be getting as much help with medication management or other essential needs from family members who are keeping their distance." And for tips on caring for the elderly in your life, check out 6 Essential Elderly Care Tips to Follow During the Coronavirus.

5 They're disoriented.

Sam Torbati, MD, medical director of the Ruth and Harry Roman Emergency Department at Cedars-Sinai Medical Center, told Kaiser Health that he's seen senior patients with coronavirus who are profoundly disoriented, similar to patients who have suffered strokes.

6 They're dizzy or falling down.

Torbati also described seeing seniors with COVID-19 who can't support themselves. "When they stand to walk, they collapse and injure themselves badly," he said.

7 They're not speaking.

In examining older adults with COVID-19, Torbati said some have been been unable to speak. "When we test them, we discover that what's producing these changes is a central nervous system effect of coronavirus," he said. And for more coronavirus facts to learn, check out 13 Actual Facts That Debunk Common Coronavirus Myths.