DOCTORS were left stunned by the mysterious case of a boy who began to spontaneously cry tears of blood.
Over a period of six weeks, the rivulets of blood leaking out of his eyes grew thicker and more frequent - often exacerbated by going to the loo.
The "alarming" case was detailed in paper published to .
The boy in his early teens first visited eye specialists in Bangalore, India, two weeks after blood began oozing from his right eye and right nostril.
The bloody tears were "painless" but "progressively increasing", doctors noted in their report.
"There was no history of recent trauma, bleeding from any other mucosal surfaces or psychiatric illness," they added.
Read more on bizarre cases
Initial tests revealed no notable abnormalities.
The boy had 20/20 vision, his tear drainage system was free flowing and there was no evidence of haemorrhages, nor were there issues with his sinuses.
But the boy returned a month later with increasing bleeding from his right eye.
Curiously, his condition seemed to be "aggravated" by peeing.
Most read in Health
The teen's eye wasn't actively leaking blood during his second examination, but medics noted that his lower eyelid showed evidence of "maceration" - when skin is broken down due to repeated exposure to moisture - and bleeding.
"The patient was asked to pass urine and frank bleeding was noted from the right eye," doctors said.
Upon further examination, it was revealed that the teen had "malformed blood vessels consistent with a vascular malformation".
After referring him to a neuroradiologist for further tests, the boy was diagnosed with "conjunctival micro arteriovenous malformation".
Arteriovenous malformations (AVMs) happen when a group of blood vessels in your body forms incorrectly, according to .
In these malformations, arteries and veins form an abnormal tangle, which usually happens during development before birth or shortly after.
These tangles can form in the brain or anywhere else in the body like the face, arms or legs, and in tissues and organs like your heart, liver or lungs, according to .
In the boy's case, an AVM was found in his inferior forniceal conjunctiva - the lower eyelid.
People who have malformations in their veins and arteries often won't experience problems.
But there is a risk of bleeding due to the vessels rupturing.
"This is the first reported case of haemolacria due to an underlying conjunctival micro arteriovenous malformation," doctors noted in their report.
Some other bizarre medical case studies
Read more unusual case studies which have even shocked doctors
- Two women were left with a lung disease after having their eyebrows microbladed
- Doctors had to pull a motorcycle brake handle from a teenager's eye after it got stuck during a horror road accident
- A man was left in excruciating pain after shoving a toothbrush into his penis which then snapped during sex
- A young girl was left unable to wear shoes and struggled to walk due to a giant big toe
- A man developed a killer lung infection after using a common cold and flu medicine every day for decades
- Horrific scans show a woman impaled by a pole after she fell on her Christmas tree
Other cases of 'bloody tears' have been caused by inflammatory conditions, trauma or use of blood thinning medications.
It was decided that the boy would undergo endovascular embolisation - a procedure that fills or closes blood vessels to prevent bleeding or rupturing.
Surgeons were able to successfully treat his condition, and the boy only experienced mild pain and swelling to his eyelid following his operation.
When medics checked in two weeks post-op, the boy had experienced no more bloody tear episodes and there was only some minor scarring at the site of the procedure.
"He continues to remain asymptomatic at six-month follow-up," they noted in their report.
"Haemolacria, characterised by spontaneous bleeding from the
ocular surface, is a rare condition," they wrote.
READ MORE SUN STORIES
"The degree of haemorrhage can range from sanguineous watery discharge to frank bleeding with a variety of causes previously reported."
Previously, a 22-year-old man in India who went to hospital after crying tears of blood left doctors stumped, as they were unable to figure out the cause.