Two years ago, my mom asked me to pick her up from a routine colonoscopy. I arrived at the outpatient facility to news that she was fine. I, on the other hand, was not. As I approached the recovery room, panic crept in. My breathing thinned, my vision clouded, a deep fog settled over my brain. I stepped through the curtain to her bed, and the rhythmic heart monitor beeps triggered acute sensory flashbacks to a few years earlier. Woozy, I grabbed for a chair. I was having, I would learn later from my therapist, symptoms consistent with post-traumatic stress disorder.

I was 32 and living in Los Angeles when I became my father’s caregiver, following his diagnosis of progressive supranuclear palsy, a rare degenerative brain disease that affects walking, swallowing and speech. Many people associate the term “caregiver” with a hired home health aide, or a family member providing constant live-in care, but the term can refer to a variety of situations from daily care to sharing in decision-making or finances. In our case, my dad needed constant supervision, so he lived in an assisted living facility in New York, and then a nursing home. But as his only child (my parents were divorced), I was responsible for and very involved in his care. I’m not unusual; according to studies from AARP, millennials make up a quarter of the approximately 40 million family members caring for adults in the country.

For two years, I made frequent trips home, staying for days or months at a time. I cut his food so he wouldn’t choke, relayed my observations when his voice weakened, researched whatever clinical trials or various therapy regimens might stave off the disease. The uncertainty and rapid progression of PSP meant there was always a new symptom to adapt to, a new complication. Unexpected hospital visits and stays became common. Each time I’d arrive terrified that the worst was happening. One day, in early September 2014, it did.

Because I was so focused on my dad’s health, I didn’t realize at the time how traumatic these hospital visits were, or that their memories would haunt me. After he passed, classic PTSD symptoms, which included intrusive flashbacks, being “dazed” when distressed, and avoiding medical settings reminiscent of his disease, recurred for a couple of years.

Research conducted on family members of intensive care unit patients at both the University of California at San Francisco and Samuel Merritt University in Oakland, Calif., found high rates of PTSD symptoms in those described as “decision-makers” (35 percent and 42 percent respectively). The ICU itself can be triggering for caregivers; sights and sounds experienced there, as well as the uncertainty and severity of the situation, may be relived through distressing flashbacks. A study of caregivers of patients in a neuroscience ICU found their PTSD rates remained relatively stable from hospital admission to six months post-hospitalization, suggesting discharge does not alleviate the emotional trauma.

“We’re increasingly thinking of caregiving as a public health issue,” said Ranak Trivedi, an assistant professor in the psychiatry department at Stanford University who specializes in caregiver stress. She explained that caregiving is a risk factor for post-traumatic stress “for the basic reason that, for a lot of people, this is a sudden, traumatic change in their life.” A phone call delivering news a family member has been in an accident and requires chronic care, or a doctor’s appointment when a loved one is given a diagnosis can be acute events, Trivedi explained, that signify a switch from “normal” life to a long, often overwhelming, road of caring.

Several studies of the chronically ill found some family members more prone to develop PTSD than others: Risk factors identified included adult children, women and caregivers of a close relation. I checked so many boxes I felt like a textbook cliche. A study of bereaved relatives of cancer patients found a long period of caregiving can also mean increased risk of PTSD for the caregivers.

Spouses who care for military veterans who have been diagnosed with PTSD have an additional risk factor: They’re vulnerable to secondary traumatic stress resulting from indirect, rather than firsthand, exposure to violent events. According to David Austern, clinical instructor of psychiatry at New York University-Langone’s Steven A. Cohen Military Family Center, if a military member shares details with a spouse about, for example, an explosion, the spouse might start to have intrusive thoughts about the explosion.

If you had told me when my father got ill that I could be at risk of developing PTS symptoms if I cared for him, my response probably would’ve been, “I’ll be fine.” Personal well-being isn’t something caregivers think about much, perhaps because many don’t have a choice about taking on this responsibility. I brushed aside any distress — such as panicking when my phone rang with an unknown number — as typical because, why wouldn’t this be upsetting? Caregivers often normalize negative responses, not realizing something deeper is at play. Making matters worse, they often delay their own mental health treatment to prioritize others’ care.

Health-care providers can, and should, take steps to aid caregivers. Researchers at Case Western Reserve University who studied caregivers of the chronically critically ill recommended that medical teams reach out early to build trust, reduce uncertainty and provide emotional support and empathy. Because having anxiety is a risk factor in developing PTSD, they also suggested early psychological screenings of family members as a preventive measure.

Trivedi emphasizes the need for the people in a caregiver’s life to be observant. “A lot of times, it’s the people around us who recognize that something is amiss. When we are ourselves distressed, ... we’re not as able to see it.” If you know someone caring for a family member, check in. If they’re less present in the relationship or social activities, is it because they’re overwhelmed by care responsibilities or bereavement, or because they are withdrawing?

If you’re a caregiver experiencing PTS symptoms, speak up. “Seek treatment if you feel like you’re not able to handle emotional distress, period, whether or not you suspect PTSD,” Trivedi suggests. Austern also recommends attending a support group. “Being able to connect with others is absolutely such a huge component because, number one, it’s pooling resources; number two, it’s also normalizing the experience in a way that individual therapy might not necessarily be able to.” Organizations such as Family Caregiver Alliance and National Alliance for Caregiving are great resources to find support; caregivers of veterans can contact VA Caregiver Support and Hidden Heroes, a program of the Elizabeth Dole Foundation. The National Center for PTSD has mobile apps for PTSD management.

Over time, with cognitive techniques, my PTS symptoms have waned. Now, when I answer the call of family medical emergencies, I react differently. Deep breathing exercises keep me present and calm as I remind myself that this is not a moment with my dad happening again. I have already lived through those events — and I have kept going.

Jennifer Levin is a writer and runs Caregiver Collective, a Facebook support group for millennial caregivers.