The reason for Christine McVie's death has been disclosed. The Fleetwood Mac keyboardist passed away due to a massive stroke, caused by an aggressive form of cancer. As per the death certificate, McVie was diagnosed with "metastatic malignancy of unknown primary origin," which had spread throughout her body, but its source was undetectable. Although cancer was listed as a secondary cause, McVie officially died from an "ischaemic stroke." According to the Mayo Clinic, this type of stroke occurs when the blood supply to a part of the brain is disrupted or reduced, resulting in brain tissue being deprived of oxygen and nutrients, which leads to the death of brain cells within minutes.