After Manthanan Arunjanpakdi, 11, was admitted to the hospital sweating blood, hematology division chief Dr Kawiwan Weerakul said doctors collected blood samples for testing but found no physical abnormality, except the girl was exhausted from lack of sleep.

Her blood sweating has now stopped and she's being closely observed by medical staff, she said.

Siriraj dermatologist Wanee Wisutseriwong said years ago she had treated another 14-year-old Phetchaburi girl with similar symptoms, later diagnosed as hematidrosis.

She cited a medical article from Brazil saying currently there were only 66 cases of hematidrosis in the world.

She said Manthanan's occasional blood sweating may be linked to her hormone cycle.

The girl's father, Police Colonel Jeerattikul Arunjanpakdi, said he had high hopes for Siriraj Hospital's treatment.

He believed it might be bad karma causing his daughter's condition so he prayed for her recovery every time he made merit, he added.

Manthanan said she felt exhausted but was hoping for good doctors to cure her so she could go back to school.