Olivia Munn has undergone a double mastectomy after being diagnosed with an aggressive form of breast cancer.

The actor, 43, detailed her path to diagnosis in an emotional Instagram post on Tuesday, which included photos from the hospital and a raw written statement.

“I hope by sharing this it will help others find comfort, inspiration and support on their own journey,” Munn’s message to followers began in the caption.

In the accompanying statement, the star shared how she’s gone through four surgeries since discovering her cancer last spring.

“I’ve kept the diagnosis and the worry and the recovery and the pain medicine and the paper gowns private,” Munn said. “I needed to catch my breath and get through some of the hardest parts before sharing.”

Diagnosing the actor’s cancer wasn’t so straightforward, according to Munn.

Even after testing negative for the known breast cancer gene BRCA and getting a clean mammogram, her physician, Thas Aliabadi, decided it was worth checking to see if she was at risk and calculated a breast cancer risk assessment score for her.

“I wouldn’t have found my cancer for another year ― at my next scheduled mammogram,” she wrote. “The fact that she did saved my life.”

Factors like Munn’s age and having her first child after the age of 30, along with family history, prompted the actor’s OB-GYN to send her for an MRI, which the star said led to an ultrasound and then a biopsy, with cancer tissue found in both breasts.

Munn described the type of cancer, luminal B, as an “aggressive, fast moving cancer.”

A month after the discovery, she underwent a double mastectomy.

Calling herself “lucky” to have found the cancer early, Munn urged readers to have their physicians calculate their Breast Cancer Risk Assessment Score.

She finished with thanks for her friends, family, partner John Mulaney, son Malcolm and her medical team.

Read Munn’s full statement on Instagram.