Angelina Jolie was diagnosed with Bell's Palsy—Here's what that means

Bell's palsy is a form of facial paralysis that results from damage or trauma to the facial nerves, according to the National Institutes of Health.

Symptoms can include twitching, weakness, or paralysis on one or both sides of the face—but luckily, in most cases, it's only temporary, according to the NIH. The condition affects around 40,000 Americans each year.

Dr. David Putrino, Assistant Professor of Rehabilitation Medicine at the Icahn School of Medicine at Mount Sinai, says that Bell’s palsy occurs when the cranial nerves (which “are responsible for a lot of the functions that go on in our head, mouth, throat and face”) are damaged on one side of the body.

“When a nerve like the facial nerve is damaged, it has to heal, and nerve healing takes a long time: Nerves heal at a rate of roughly six millimeters (just less than a quarter inch) every week,” Putrino says of the recovery process. “Once the process of nerve healing begins, however, physical therapy becomes very important to help the muscles of facial expression and facial sensation recover normally as the nerve heals and re-innervates its old territory.”

In the interview, Angelina credits acupuncture with helping her make a full recovery. But while many patients, like Angelina, seek alternative therapies like vitamins and acupuncture for faster results, Putrino is quick to say that “none of these methods have solid scientific evidence to back them yet.”

The actress also implied that her Bell's palsy may have been brought on by stress, noting that she also developed hypertension, dry skin, and started noticing more gray hairs. She told VanityFair,"Sometimes women in families put themselves last, until it manifests itself in their own health."

Putrino says there's no science directly linking Bell's palsy and stress. However, “hormonal changes and high stress may be responsible for triggering things like viral reactivation, or make you more susceptible to bacterial infections, all of which can lead to Bell's palsy,” he explains.

Some of the things that can cause Bell’s palsy, according to Putrino, include “reactivation of viruses such as Epstein Barr or herpes simplex, certain bacterial infections, or even physical damage to the nerves because of trauma or growth of a tumor.”

This isn't the first time Angelina has been candid about her health. She's talked in the past about testing positive for the the BRCA1 gene, and has been open about her preventative double mastectomy, as well as her decision to have her ovaries and fallopian tubes removed. Kudos to Angelina for being open once again.