All of these people have something in common. They are immunosuppressed.

They're living with an invisible illness. Social distancing will save their lives

Updated 5:58 PM ET, Thu March 19, 2020

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(CNN)While there's concern for the elderly catching coronavirus, there's another high-risk group that has nothing to do with age.

People with underlying medical conditions are also more likely to become seriously ill if they get it.
Some of them are young and most of them may not look sick at all. Millions of them are living with a compromised immune system.
It's estimated that about 3% of the adult US population is immunosuppressed, according to a 2013 National Health Interview Survey. That's roughly 7 million people living with a weakened immune system today.
Some of them have a disease that's weakened their immune systems. Others are taking immunosuppressants for cancer or organ transplants.
Coronavirus has made life a lot harder for the immune-compromised. These are some of the challenges they're facing:
There are days when Brittania Powell can't get out of bed.

They may not look sick, but they have an invisible disease

Brittania Powell is a college student with a bright smile and a love for the food of her native Jamaica. She goes to class and works at a caterer, but what many don't know is that she's dealing with several conditions they can't see.
    On a good day, Powell can walk to class at Columbus State Community College in Ohio. On a bad day, she can't bend her knee enough to walk.
    She can wake up to any joint in her body being swollen and inflamed and she can't predict when it'll happen, she said.
    Powell was diagnosed with the autoimmune disease lupus when she was 14. She also has rheumatoid arthritis, anemia and lupus nephritis, which inflames her kidneys.
    "Lupus and other immune-compromised diseases, a lot of them are invisible diseases," Powell said. "I realize that it's hard for people to take it seriously, acknowledge it or even think about it on a daily basis if they can't see it."
    Powell wants people to know that just because she looks healthy, that doesn't mean she is. She hasn't left her place in more than 10 days because she wants to avoid getting coronavirus.
    "There are people out there that may look completely healthy and bright, but on the inside, we're struggling," she said.
    Powell hopes that people take "others into consideration," she said. Do little things, such as washing your hands and coughing into your sleeve, that make a big difference for someone who's immune-compromised.
    Danielle Grijalva is self-isolating to protect herself from getting sick.

    Self-isolating is a struggle that's not new them

    When flu and cold season comes around, some people with weakened immune systems go into self-isolation mode, like Danielle Grijalva.
      That practice started when the mother of two woke up not being able to walk one day in 2015. She lost her career and the old life she knew.
      The 44-year-old Californian became homebound and wasn't able to walk, drive or do the things she needed to do, she said. It took three years until she had the diagnosis of a pain condition called fibromyalgia, chronic fatigue syndrome and several strains of echoviruses, which were found in her stomach.
      "I know how much that that lack of independence sucks," Grijalva said. "But for us that are immune compromised, that's something that we deal with all the time."
      Healthy people are just getting used to isolating themselves at home as coronavirus spreads. For Grijalva, it's always been a measure to protect herself.
      "Now they're kind of understanding what we have to deal with on almost a daily basis," she said. "It's not that we're germophobes. It's not that we are wanting to be introverts and stay home and be home bodies. It's that we have to do this in order for us to not to get so deathly sick."