Do you seem to get sicker than when you were younger? When you are bad, does it take you longer to feel good again?

Immunity (the body’s defense system) tends to weaken with age.

“Just as you probably can’t run as fast as you used to in your 20s, your immune system doesn’t work as well as it used to,” says Aaron E. Glatt, MD, chair of the department of medicine at South Nassau Community Hospitals.

But don’t be afraid, at least not too much.

“Compared to many other bodily functions, most people’s immune systems function really well at any age,” Glatt says. Most of our immune systems work well enough that our risk of infection and disease is not much higher than normal. Even better? No matter how old you are, there are many things you can do to stay healthy.

It is a complex network of cells, tissues and organs. Together, they defend your body against things that can cause infections, such as bacteria.

Why does it ease a little as you get older? That remains a mystery.

“The medical community is still trying to determine exactly how and why immunity declines with age,” says Kira Rubtsova, PhD. Rubtsova is an immunity researcher at National Jewish Health in Denver.

What researchers do What we know is that most older adults:

Does not respond as well to vaccines: Your immune system includes T cells, which attack other disease-causing cells. They are able to “remember” an invader and then better defend themselves against them. When you are older, you produce fewer T cells, and most vaccines require new cells to work.

The exeption? The shingles vaccine. That’s one of the reasons it works so well for the senior group.

They are more likely to get sick: Not only do you have fewer immune cells as you age, but the ones you do have also don’t communicate with each other. That means they take longer to react to harmful germs.

Recover from injuries, infections and illnesses more slowly: “The body produces fewer immune cells, including white blood cells,” says Rubtsova. “That can slow down healing.”

There is no set age at which immunity wanes.

“It’s like gray hair: it happens to everyone at a different rate,” Rubtsova says. There is no single test that can tell you that his immune system is not working optimally. “There are certain immunological markers that we can test for, but it’s not the same as, for example, testing for heart disease,” Glatt says.

That’s why it’s important to see your doctor regularly and get medical help if you get sick frequently or have trouble recovering after an injury or illness.

Stay on top of your health. if you have diabetes, arthritisor other things that affect how you feel and how you function, follow your doctor’s recommendations. “Keeping diseases like diabetes well controlled has less impact on the immune system,” says Glatt.

Sleep well. “Research clearly shows that too little sleep (or poor-quality sleep) reduces immunity, even in young, healthy people,” says Dr. Gisele Wolf-Klein. You should sleep at least 7 hours a night. If you snore or have trouble falling or staying asleep, see your doctor. You could have a sleep disorder.

Look for ways to reduce stress. Over time, stress can decrease your immune response. “When you’re constantly worried about something, it takes a toll on your body,” Wolf-Klein says. It can also trigger other problems, such as poor sleep and poor diet, which can affect your immunity.

Stay away from sick people. “The truth is, when you’re older, you have to be especially careful about exposure to germs, because you’re also more likely to get sick,” Wolf-Klein says. When you are around people who have contagious illnesses, such as a cold or flu, try not to get too close and wash your hands more often.

Don’t skip vaccines. Although they may not be as effective when you are older, they are still an important way to reduce the risk of many serious illnesses, including the flu and pneumonia. Check with your doctor to make sure your vaccinations are up to date.

Move more often. Moderate exercise helps you stay fit, which strengthens your immune system. Research also suggests that it helps cells move more freely, which helps them do their jobs better.

Eat well. There is no diet that improves immunity. But researchers do know that a varied diet full of foods rich in vitamins and minerals (like fresh fruits and vegetables) helps your body, including your immune system, function at its best. Eating a healthy diet also helps you weigh what you should, which can put less stress on your body and improve immunity.

Do not smoke. Smoking weakens your body’s immune response, making you more susceptible to diseases and infections. Your doctor can help you find out how you can quit smoking.