The 'Friends' and 'Dead To Me' actor has revealed her MS diagnosis on Twitter.

Christina Applegate has disclosed online that she has been living with Multiple Sclerosis for the past few months. The actor, who turns 50 this coming November, posted her news on Twitter early Tuesday morning.

MS is an autoimmune disease that can affect the brain and spinal cord and is a lifelong condition. People who are diagnosed with MS can live a normal life, although their life expectancy can be five or 10 years shorter than the average person.

Christina wrote on Twitter: "Hi friends. A few months ago I was diagnosed with MS. It’s been a strange journey. But I have been so supported by people that I know who also have this condition. It’s been a tough road. But as we all know, the road keeps going. Unless some asshole blocks it."

She then posted a further tweet, quoting a friend who has lived with MS while asking for privacy while she battles the condition. She wrote: "As one of my friends that has MS said 'we wake up and take the indicated action'. And that’s what I do. So now I ask for privacy. As I go through this thing. Thank you xo"

Christina Applegate has been known for her multiple comedic roles in TV and film since the '80s and '90s. Her breakout role was in 'Married... with Children' as promiscuous daughter Kelly, while she also played Rachel's self-absorbed sister Amy in two episodes of 'Friends' (which she won an Emmy Award for), an amnesia sufferer in 'Samantha Who?', and not forgetting her part as Veronica Corningstone in both 'Anchorman' movies.

Her most recent TV role has been in the popular Netflix series 'Dead To Me' alongside Linda Cardellini and James Marsden. A third and final season is due for release in the future.