She continued: "It is a chronic condition - no cure yet - and it does mean my immune system is a bit compromised, so I will need to take good care of myself and I will be carefully monitored with blood tests, MRIs and bone marrow biopsies (which I have recently discovered are even less fun than they sound).

"It's been a lot, especially coming less than two years after my last diagnosis, but l know that seeing others in the public eye cope with comparable situations has helped me, so I thought I'd be upfront about it."

She also thanked her doctor. "This is the second Big Problem my GP has caught early and it is frankly impossible to adequately express my gratitude," she wrote.

"I was pretty blasé about my persistently low iron levels but he insisted we get to the bottom of what was going on.

"My message to others would be: be like him, not me! Advocate for yourself if you need to and ask to see a haematologist if you are in the same situation."

Laverne said she is now taking a couple of weeks' holiday and "will be back to work as normal after that".

She added: "For now lots of love, especially to anyone dealing with similar issues. LL xx"

According to Myeloma UK, external, smouldering myeloma is detected by the presence of abnormal cells in the bone marrow, and abnormal protein in blood and/or urine.

Patients are regularly monitored for signs that they are developing active myeloma or related conditions.

Smouldering myeloma usually develops into active myeloma at some time, but how long that takes varies, according to the charity.