A woman sits cross-legged on a couch, under a blanket, blowing her nose

From our skin to our blood cells, our bodies have a variety of tools that help us resist infections—which occur when germs such as bacteria or ­viruses invade the body, multiply, and potentially cause illness—and keep them from becoming too serious when they take hold. But that can change as we get older.

The aging process and the presence of chronic conditions can make the immune system less effective at preventing infections, says Robin Jump, M.D., an associate professor of medicine at Case Western ­Reserve University in Cleveland.

Infections can also be hard to pinpoint and more likely to lead to serious complications in older adults. Here’s how to stay safe.

Spot the Signs

Fever is thought of as a hallmark of infection, while other common symptoms may include coughing and sneezing, nausea and vomiting, fatigue and malaise, and worsening pain and swelling in the case of skin or wound infection.

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But infections may manifest differently in older adults. For instance, in younger adults, doctors usually consider a fever of 100.4° F as an indication of a serious infection. But with age, our bodies tend to run colder: An infection-related fever may rise only to 99° F in frail older people, for example. In pneumonia, some older adults might not have typical symptoms, such as chest pain or coughing.

What to do: Watch for typical symptoms, such as cough or sore throat, as well as less familiar signs. In some cases, infection in older adults can cause confusion or disorientation, falling, and appetite loss. These symptoms on their own don’t necessarily signal an infection, but they warrant a call to your doctor, who can help you rule out other possible causes. 

Seek the Right Treatment

It’s important to get treatment if you need it. But unnecessary medication use can mean potentially dangerous side effects for no benefit, particularly with antibiotics.

A 2017 Canadian study published in Annals of Internal Medicine found that 46 percent of people 66 and older who were diagnosed by a doctor with nonbacterial bronchitis, sinusitis, or laryngitis received a prescription for an antibiotic. These drugs are ineffective for viral illnesses and, when used without good cause, contribute to antibiotic resistance.

What to do: If you notice nonspecific symptoms, such as confusion, falls, and a loss of appetite, let your doctor know you don’t want to take antibiotics unless they’re indicated. Ask whether a non­infectious problem, such as dehydration or the side ­effects of a medication you’re using, could be the cause. 

Watch for Serious Symptoms

Older adults are at an increased risk of a severe complication from an infection. The worst-case scenario, Jump says, is sepsis, a powerful response to infection that can lead to organ failure or even death.

While the death rate from sepsis appears to be falling, the overall number of cases is on the rise, according to a 2016 study published in the Journal of Critical Care.

But predicting who will develop sepsis and diagnosing it is challenging, says Theresa Rowe, D.O., assistant professor of medicine in the division of geriatrics at Northwestern University in Chicago. The signs, including difficulty breathing, fever, confusion, clammy or sweaty skin, and extreme pain or discomfort, are easy to confuse with symptoms of other conditions. But identifying and treating sepsis early (with antibiotics and sometimes other therapies as well) is critical.

What to do: If you get sick, ask your doctor how long your infection is likely to last. Alert her if symptoms such as fever and vomiting aren’t improving or are inten­si­fying when they should be easing up.

And attend to skin infections: See your doctor if you have a cut or wound with pain, redness, or swelling in the area that’s worsening instead of getting better, says Lisa Gould, M.D., Ph.D., associate medical director of the South Shore Health Center for Wound Healing in Weymouth, Mass. In these situations, it’s wise to ask your doctor whether sepsis might be a possibility­­­—so you can get a diagnosis and treatment quickly. 

Editor’s Note: This article also appeared in the January 2020 issue of Consumer Reports On Health