A 46-year-old terminally ill woman in California has filed a lawsuit against the state, asserting that the law allows doctors to help patients with critical illness end their lives.

Christy O'Donnell is fighting for her right to decide how she will die after she was diagnosed with stage-4 lung cancer last year.

She said that the chemotherapy sessions she went through were not able to stop the cancer cells from spreading to her brain.

The doctors told O'Donnell that she only has a few months to live, and that her death will be slow and painful.

"The most likely way that I'm going to die with the lung cancer is that my left lung will fill with fluid," O'Donnell said in a video recording. "I'll start drowning in my own fluid."

O'Donnell said she was inspired by the story of Brittany Maynard who sought the help of a group named Compassion & Choices.

Through the group's aid, Maynard and her husband, Dan Diaz, were able to migrate to Oregon so she could end her life under the state's Death with Dignity law.

Maynard was diagnosed with terminal brain cancer in January 2014, and she died in November of the same year.

In her video recording, O'Donnell said that she had an incredible life, and in that life she was able to experience the happiness of being a mother. She explained that, while she is not afraid to die, it does not mean that she wants to die.

O'Donnell pointed out that she could go to a hospital to have doctors painfully drain the fluids from her lungs, but they will only be filled with fluids again. She said that the process of having to drown painfully will only repeat for as long as she lives.

According to O'Donnell, this is the reason why she seeks to have a choice on how to end her life.

With a physician-aided death, O'Donnell said, she would be able to ask a prescription from a doctor.

She could then have the ability to decide on whether or not to take the prescription. She could also choose when and where to do it and with whom she could do it.

On behalf of O'Donnell and two other diagnosed with terminal disease, members of the Compassion & Choices filed a case in California last week to assert the legality of choosing to die through medical aid.

O'Donnell said she would like to have the opportunity to end her suffering by asking for a prescription should the pain become too unbearable for her.