Edwina Bartholomew reveals she has chronic myeloid leukaemia ...

Sunrise presenter Edwina Bartholomew announced in a live segment on Friday morning that she has cancer.

Bartholomew's chronic myeloid leukaemia (CML) was first diagnosed in July and she will be reducing her work hours to a few days a week when she returns from leave.

"I have personal news this morning," she said.

"It's not great news. I have been diagnosed with cancer."

The 41-year-old said she "will be completely fine" and is optimistic.

"Despite appearances, I feel really positive about it," she said. 

"It genuinely is the luckiest unlucky thing to ever happen to me. I’m just beyond grateful I found it."

So what is CML and how can it be treated?

What is chronic myeloid leukaemia?

It's a relatively rare type of cancer that affects blood and bone marrow.

According to the Leukaemia Foundation, CML is diagnosed in about 330 Australians each year.

It's caused by a chromosome mutation that occurs spontaneously and causes bone marrow to produce too many white cells. 

"These cells gradually crowd the bone marrow, interfering with normal blood cell production," the Leukaemia Foundation says.

CML mostly affects adults aged over 40 years. 

What are the symptoms?

Bartholomew said she had no symptoms when she was diagnosed.

That's common for people in the early stages of CML because the disease develops slowly, the Leukaemia Foundation says.

As it progresses, symptoms can include:

Anaemia, including persistent tiredness, dizziness, paleness or shortness of breathIncreased and unexplained bruisingFrequent or repeated infections and slow healingPain or discomfort under the ribs on the left sideExcessive sweatingUnintentional weight lossHow is CML diagnosed?

The disease can be diagnosed by examining samples of a patient's blood and bone marrow.

The presence of abnormal leukaemic blast cells can suggest you have CML.

But doctors would need to confirm this with a bone marrow biopsy, the Leukaemia Foundation says.

A bone marrow sample can show the number and type of cells present, as well as the amount of blood-forming activity taking place.

CML diagnoses are confirmed if the Philadelphia chromosome or BCR-ABL gene is detected in bone marrow cells.

How is it treated?

The course of treatment depends on which phase of the disease a person is in, as well as their age and general health.

Bartholomew told viewers the condition can be "treated with a daily tablet".

"If I can take care of myself, I will be completely fine," she said.

The Leukaemia Foundation says most people diagnosed with CML can be treated with drugs called tyrosine kinase inhibitors (TKIs).

They come in pill form and prevent the growth of leukaemia cells.

Most people need to take the medications for life to keep CML under control.

But because TKIs are very effective at controlling the disease, most people with the disease have a normal life expectancy.

For the small number of people who don't respond well to TKIs, doctors may consider a stem cell transplant.

Can CML be cured?

A bone marrow transplant is the only way to cure CML.

The procedure presents serious risks and has a high rate of complications though, so doctors usually reserve it for people who don't improve by taking TKIs.