Right now, 40 million Americans are doing truly selfless work by serving as unpaid family caregivers for a loved one. About 25 percent of those caregivers are millennials, who often feel forced to choose between their careers and caring for their aging parents and grandparents.

I can relate. When I was in my thirties, my brothers and I cared for our mother throughout her stage 4 breast cancer diagnosis. It’s not a role I was expecting to land, it didn’t come with much preparation, but it turned out to be one of the most rewarding things I’ve ever done — and, undeniably, one of the most difficult.

Caregiving for a loved one is a role that millions more Americans will take on in the coming decades — especially with so many baby boomers saying they want to age in place instead of entering retirement homes or care facilities. There are many upsides to being cared for by devoted and well-trained family caregivers, including a reduction in hospital readmissions and a chance for families to bond during a difficult time. But the caregivers themselves often end up paying a high cost, both physically and financially, which is rarely discussed.

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The mental, physical and emotional stress of caregiving (which often goes unreported and untreated until it’s too late) has created a vast looming problem for our health care system, yet few caregivers feel comfortable discussing these challenges.

So I’ll go first.

When my brothers and I stepped up to serve as my mother’s caregivers, we did everything we could to support her, from hospitals to hospice care. This often meant trying to figure out and manage her medical paperwork, medication schedules and in-house help, and continually redefining an ever-changing “new normal” for all of us. I often felt overwhelmed, and that was even with all the support I had from my brothers and colleagues.

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Caregivers must embrace self-care

Many caregivers aren’t as lucky as I was. A recent study by the National Alliance for Caregiving found that a third of caregivers in America do it alone, without any paid or unpaid help — and this uphill battle can lead to a domino effect of health and financial problems for the caregivers themselves.

When you’re caring for a loved one, there’s nothing you won’t do (or sacrifice) to give them as much comfort and peace of mind as you can possibly provide. Often, that means you’ll skip your social obligations, wreck your diet, suffer sleep deprivation, and even risk your career, all to help a loved one through the most difficult time of their life.

Rob Lowe attends The Comedy Central Roast of Rob Lowe at Sony Studios on August 27, 2016 in Los Angeles, California.

Over time, the stress of caregiving can lead to long-term health problems. A 2017 survey by Embracing Carers found that roughly half of unpaid U.S. caregivers suffer from feelings of depression (49 percent), sleep trouble (57 percent), weight fluctuation (46 percent) and other health complications — and that’s before stress related to money even enters the discussion.

MetLife recently found that caregivers are sacrificing almost $3 trillion a year in lost wages, pensions and Social Security benefits. That number doesn’t include the $7,000 on average that every caregiver personally spends each year to provide services for their loved one. And while some states and companies have improved their family leave policies, many caregivers still must use their own personal, vacation and sick time to care for their loved ones. This means if the caregiver gets sick, he or she will just have to power through ... until they simply can’t.

It doesn’t have to be this way.

Caregiving won't last forever — make it worth it

I had the opportunity to collaborate with EMD Serono and Embracing Carers, who are dedicated to increasing awareness of the challenges that family caregivers face and helping to advocate on their behalf. What I’ve learned along the way is that many caregivers don’t feel supported, they don’t know where to turn for help, and they often suffer stress-related health problems of their own, yet the last thing on their minds is their own well-being. The irony is that to effectively care for someone else, we caregivers must first remember to take care of ourselves.

From my own experience, I can assure you: The person you’re caring for needs you to be at your best. If you don’t take care of yourself, you won’t have the energy or the means to provide the reliable care that your loved ones need. But what can you do for yourself, especially if you feel like you don’t have enough time as it is for your job, your family and your caregiving duties?

Ask for help.

My brothers and I had each other, but many caregivers — like my stepmother — have no direct help to rely on. Luckily, the internet is filled with support groups, forums and other resources where caregivers help each other by sharing advice and providing a shoulder to cry on when the going gets tough.

Likewise, talk about the challenges of caregiving with your family, friends and co-workers. The more aware we are of the realities of caregiving, the more actions we can take to improve the experience for everyone. Plus, the people in your life might want to help you in your act of caregiving, but they might not know how to bring it up. By starting the conversation, you give them an opportunity to ask their own questions and find their own way to lend a hand.

Finally, just be present. I know that caregiving can feel like an overwhelming array of details and responsibilities, prescriptions and pill charts, nonstop schedules and sleepless nights, which could make each day feel as if you’re scaling a mountain of stress. But time passes, and life does go on. When your caregiving experience ends, you’ll want to look back and see that you did the most important thing: simply helping someone you love know that they weren’t alone.

Rob Lowe has been nominated for two Emmys, six Golden Globes, and four Screen Actors Guild awards in which he won two. Follow him on Twitter @RobLowe

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This article originally appeared on USA TODAY: Actor Rob Lowe: I was my sick mother's caregiver, don't underestimate the stress caregivers face