Comedy actress Miranda Hart has described how suffering with Lyme disease has affected her whole adult life and at one stage left her confined to bed.

The TV star, best known for popular BBC sitcom Miranda, has spoken about being diagnosed with the debilitating condition after years of wondering what was wrong with her.

Hart, 51, said she first became unwell aged 15 and her illness developed into chronic fatigue and myalgic encephalomyelitis (ME).

Miranda Hart has spoken of living with undiagnosed Lyme disease her whole adult life (Daniel Leal-Olivas/PA)

It culminated while in her mid-40s in a collapse which ats its peak left her confined to bed, with doctors struggling to diagnose the illness.

“I’ve not felt well since I was 15. It got progressively worse,” she said.

“But yes, since I was 15, I’d say I’ve never had full energy. I never felt refreshed after a night’s sleep.

“I could never… I’d see people would go out after work or go to a party, and then go to school and think, how are you doing that?

“I just felt quite weak all the time and very strange neurological sensations as well, which doctors couldn’t explain, I had every sort of test.

“But yes, I’ve never felt well.”

The comedian and actress was speaking at the Cheltenham Literature Festival to promote her new book, I Haven’t Been Entirely Honest With You.

At one point, doctors told her there was nothing wrong with her but eventually she was diagnosed with Lyme disease – a bacterial infection that can be spread to humans by infected ticks.

“In my case, my level of illness, it was never acute, I wasn’t going to collapse and die of it, luckily,” she said.

“But I kept saying to doctors, I know I’m leading a half-life, I’m leading a very debilitated life but with no understanding of why.

“And it was almost like I kept saying, eventually, as the years went on, I said, if this was a named condition and this is how you manage it, then I could handle it, I could dig in.

“I think the hardest thing about these sort of fatigue-based conditions, whatever they come from, is that lack of understanding, lack of never knowing when there’s an end date, no management plan.”

Hart said a doctor told her in 2007 she may have chronic fatigue and suggested she take six months off work, which she said she could not as her career was beginning to take off.

“It wasn’t clear what chronic fatigue was or what I should do, so I carried on. I was functioning okay, but I had to manage my energy very well.

“I think at one point when I was writing Miranda I had a virus or something every six weeks.

“I was just up against it, just like waiting to be treated.”

She told the audience that after completing the final series of Miranda she collapsed on her sitting room floor through exhaustion, which she described as a “massive relief”.

“So actually when I collapsed, I was able to say, ‘I can’t go on’. There was this massive relief,” she said.

“My body stopped me, and I remember having enough sort of consciousness, as it were, to say, ‘This has to be the beginning of it, this has to be, this will be my change point’.”

She explained that to put it simply, she has ME caused by Lyme disease.

“Some very clever experts finally sort of joined the dots back to when I first started feeling unwell was when I was living in a Lyme hotspot in Virginia in America, when my father worked out there,” she said.

“So, and I remember getting the flu there, which was really peculiar, and I didn’t recover for ages from it, and we just joined the dots.

“So, I lived with a reactivated Lyme since I was 15, which then plays havoc on your immune system, disorders your immune system, then any other virus you get, it’s very hard to recover from that, so other viruses get reactivated, then shingles got reactivated in me, and later it just…

“So, it’s like having flu all the time. With flu you sort of sleep, but you feel like you’ve never slept.

“It’s that, but yet you’re being told there’s nothing wrong and you’ve got to carry on. It’s not fun.”