Christina Applegate: Person Transported From Her Home to Hospital Days Before MS Announcement

A patient was transported to the hospital from Christina Applegate's Los Angeles home just days before the actress revealed she'd been misdiagnosed with multiple sclerosis ... TMZ has learned.

A spokesperson for the Los Angeles City Fire Department tells TMZ ... paramedics were dispatched to Christina's Hollywood Hills home on October 17 for a patient reportedly experiencing abdominal pain.

We're told the patient was transported to a local hospital for medical treatment. It's unclear who the patient was or whether the medical emergency had any connection to Christina.

The incident occurred just three days before Christina revealed Tuesday she doesn't actually have MS ... despite believing she'd been battling the disease for more than five years.

As we reported ... Christina returned to her "MeSsy" podcast with cohost Jamie-Lynn Sigler, revealing doctors had determined she'd been misdiagnosed with the disease.

Despite the change in diagnosis, Christina made it clear her health struggles are far from over, describing her situation as "the same game with a different name."

The actress explained that losing the MS diagnosis hasn't made her symptoms disappear, telling Jamie she hasn't gotten better and, in some ways, has actually gotten worse.

During a second episode, Dr. Marwa Kaisey, a Cedars-Sinai neurologist, explained MS misdiagnoses are "fairly common," affecting about 1 in 5 patients.

She stressed that changing a diagnosis doesn't change the symptoms, saying, "The symptoms don't go anywhere," and treatment remains focused on managing them.

Christina has been open about her ongoing health struggles, including multiple hospital visits and medical treatments, which she's regularly discussed on her podcast.

As we first reported ... Christina was hospitalized in Los Angeles from late March until August. The reason for her lengthy hospital stay was never disclosed.