Lala Kent rushed her daughter to hospital after the youngster started "gasping for air".
The 'Vanderpump Rules' star was left worried when 18-month-old Ocean - who she has with former partner Randall Emmett - became distressed after being put to bed and took her to the emergency room to get checked out because "something was off" with the toddler.
Speaking on her 'Give Them Lala' podcast, she said: “I put her down on Wednesday night, I hear her upset. And people always ask, ‘Did you sleep train Ocean?’ And I did, because I feel like you know their cry. This cry was, ‘Something’s wrong.’ "
Lala told listeners Ocean was “gasping for air like she cannot breathe" but she thought it was a good sign the toddler was "screaming" because “if she really couldn’t breathe, that wouldn’t have been possible.”
After observing her daughter for "what seemed like an hour but was really maybe about five minutes", the 'One Shot' actress decided to take her to hospital.
She said: “Something was off.
“I was watching her, I tried to lay down, I was steaming the shower, [and] while it was steaming, I put her on my chest, laid in the bed and just the way she was sounding, you could tell she was having trouble breathing. Now I’m not f****** around."
Doctors at Cedars-Sinai Hospital in Los Angeles agreed to see Ocean "immediately" and eventually diagnosed her with croup - an infection of the upper airway - which Lala admitted could be "very, very scary" for an infant but is fortunately treatable.
Though "everything is going to be fine", the 32-year-old star admitted she was "in hysterics" at the time.
She tearfully said: “Even talking about it now, it was like, ‘Oh my God this is so scary.'
“Like I asked the nurse, ‘Is my baby going to wake up tomorrow? Because I’m freaking out.’
"I don’t know what the f*** is going on. All I know is that my baby woke up and was having a hard time breathing.”
The toddler is now back at home and doing well.