It’s normal for a parent to feel a little bit sad in the days or weeks after giving birth. For a new mom, that’s usually a result of the rapid-fire hormonal changes going on in her body. And surprisingly, that’s the case for dads, too: while we don’t exactly know why this happens, there’s evidence that testosterone levels in men drop during the postpartum period, which can be linked to depression.

Sometimes, these hormonal shifts are minor and temporary. But sometimes, they can trigger serious mood changes like extreme sadness, anxiety, or feelings of hopelessness. Throw in the sleep deprivation that comes with new parenthood, and these symptoms are exacerbated tenfold.

If you or your partner seems irritable, withdrawn, or moody for longer than two weeks at a time, that could be a sign of PPD — and it shouldn’t be dismissed or ignored.

“Looking back, I was in denial about my wife’s PPD,” says Nick*, a dad to five. When she first exhibited symptoms, he chalked them up to other life stressors, which he says made it tougher for him to realize that she needed help.

The stigma associated with PPD means that it’s often difficult for people to understand what it actually looks like. “I used to think that PPD meant that the mom was totally disinterested and uninvolved with the child,” says Isaac*, whose wife struggled with PPD. “That wasn’t the case with my wife. She was—and still is—the best mom I’ve ever met, and she was totally in love with our son.”

That’s why it’s important to familiarize yourself with what the symptoms of PPD actually are, including feelings of sadness or hopelessness, mood swings, crying jags, and loss of appetite. (In very rare cases, a parent with PPD might express concern over hurting themselves or the baby, at which point you should contact a doctor immediately.)

If your partner talks about feeling overwhelmed, or expresses concern that she isn’t able to bond with the baby, that’s a red flag. “If your partner seems like she isn’t doing well, ask her how she’s feeling, and really sit and listen to what she says,” says Neill Epperson, MD, Director of the Penn Center for Women’s Behavioral Wellness at the University of Pennsylvania. Asking is key, because a new mom might be hesitant to share any negative feelings on her own. “She might be concerned about not appearing like a good enough mother,” Epperson says.

If you suspect your partner might have symptoms of PPD, remember that PPD is a medical condition that requires professional medical attention. It’s not something you can solve on your own. “During my wife’s recovery, I had to set the ‘fix it’ mentality aside and just make myself available to listen,” Nick says.

That applies if you suspect you have PPD as well: your partner is there to listen to you and to provide support, but they are not there to treat you. Only a licensed medical professional can do that.

Extreme exhaustion, isolation, and lack of support are all triggers for PPD. So even if you or your partner is seeing a therapist or taking meds, the two of you will probably need to make some changes at home.

If your partner is the one who’s struggling, find ways to lighten her load: for instance, John*, a dad of two, took on nighttime feedings on the weekend so his partner could get more sleep. If you’re the one who’s struggling, and your schedule makes it harder for you to take on more, don’t be afraid to ask for help. Enlist the help of friends or family members, even if it’s just to bring over a meal or do a few loads of laundry. Or consider hiring a postpartum doula who can help with basic newborn care.

If your partner is visibly struggling, you probably want to do everything you possibly can to help her feel better. But that could inadvertently add even more stress to your relationship.

“I thought it would be helpful to try to make things like they were before the baby romantically,” Isaac says. “But that just made things worse by putting added pressure on her not only to perform as a mom but as a romantic partner too.”

If your relationship is under a bit of strain, be patient and supportive. Ask your partner how you can help, but “try not to get exasperated if she doesn’t know right away how you can be helpful,” Epperson says. And when she does tell you, don’t second-guess her. Just do it.

It’s easy for new parents to fall into the trap of devoting all their energy to a new baby. But don’t focus on your little one to the degree that you end up neglecting your partner, or your own mental health. “You should be there to help with the baby at all hours,” Nick says. “But don’t forget your partner’s needs as well.”

You might not have the time (or energy) to go out to dinner or give your partner a long massage. But you can always find a few minutes to check in and gauge her emotional barometer. “Just say, ‘hey, how are you feeling’?” Epperson says. Your partner “is probably going to appreciate [you just asking].”