Did you know that there are people who cry tears of blood?

Have you ever heard of a real case of someone who cries blood? It is a rare condition and some cases have been reported worldwide, some being the result of so-called hemolacria and others that still intrigue doctors.

Hemolacria is a condition that refers to the presence of blood in tears. In some cases, blood concentrations may be so low that they can only be detected with laboratory tests. On the other hand, in the most extreme cases that most surprise people, the patient seems to bleed a lot from the eyes.

Hemolacria usually appears as a symptom of a disease, although it may also develop spontaneously in some cases, particularly in women of childbearing age. Injuries, infections and inflammation can also be the cause of the condition, as well as lack of blood clotting.

But there are still some cases where nothing was found wrong with patients, making the phenomenon a mystery and a source of speculation. Check below what is known about people who cry blood and some cases reported in the world.

1 - Hormonal changes can trigger the phenomenon.

In one of the oldest reported cases of hemolacria, 16th-century Italian doctor Antonio Brassavola wrote about treating a nun who cried tears of blood when she was menstruating.

At about the same time, in 1581, a Belgian doctor recorded a 16-year-old girl of the same occurrence, reporting that she "discharged her eyes like drops of blood instead of wiping her out of the womb. " The idea may seem strange, but modern science supports this concept.

According to a 1991 study of 125 healthy people, menstruation contributes to occult hemolacria, which causes traces of blood in tears (but hardly noticed by people). So much so that 18% of women of childbearing age had blood in their tears.

The study also showed that only 7% of pregnant women and 8% of men studied have occult hemolacria, while postmenopausal women show no signs of bloody tears.

Thus, scientists concluded that the condition in the occult form appears to be hormone-induced, while the most visible hemolacria is most often caused by local factors (bacterial conjunctivitis, environmental damage, injury).

2 - Several cases in the US state of Tennessee

In the last five years, there have been two notable cases of hemolacria: Calvin Inman's and Michael Spann's. The curious thing about this story is that they both live in the US state of Tennessee, and doctors have yet to find out why they cry so much blood.

In 2009, when Calvin Inman, who lives in Rockwood, was 15 years old, he got out of the bath and noticed red tears covering his face when he looked in the mirror: he thought he was dying. The teenager was rushed to the local emergency room, but doctors could find no explanation about the strange case. A battery of tests was performed, but nothing abnormal was detected.

Already Michael Spann of Antioch was coming down the stairs one day when he felt a crippling headache and noticed that tears of blood began to well up in his eyes. "I felt like I'd been hit by a hammer in the head, " he told newspapers at the time.

Moments later, he noticed that the blood was not only coming out of his eyes, but also from his mouth and ears. Although nothing unusual has been detected in Michael, he says the phenomenon is always preceded by a severe headache and also when meeting new people or experiencing stress.

Although it can be an (understandable) cause of panic, crying blood is usually not fatal. But it can be a little cumbersome and awkward. Michael also said he was fired after his employers noticed blood running down his face and since then he has become a prisoner. So far, the cases of these two boys from Tennessee are still unexplained.

There are also cases elsewhere in the world, such as the 20-year-old Chilean girl named Yaritza Oliva, who in June 2013 began to cry blood. Doctors ruled out the possibility of any likely causes, such as conjunctivitis or blood clots.

3 - In some cases, the condition disappears

Almost as unexpectedly as the tears of blood begin, they also end. "Most of the patients were relatively young, " said James Fleming, an ophthalmologist at the Hamilton Institute of Ophthalmology, who conducted a survey of patients with hemolacria in 2004.

"As they grew, the bleeding gradually decreased until it stopped completely, " said the researcher. Michael Spann himself has seen the frequency of tears of blood decrease over the years - he has been in the condition for about seven years. What was once a daily occurrence now happens once a week.

4 - Some diseases cause hemolacria

In March 2013, a Canadian man was walking along the beach when a poisonous snake stung him, causing him to weep tears of blood and painful swelling and kidney failure. Doctors attributed this to the huge amounts of internal bleeding caused by snake venom.

However, in most cases, haemolacria is caused by head trauma, a tumor, a blood clot, a tear in the tear duct, or a common infection such as conjunctivitis. Only the rarest cases above - where none of these diseases have been found - remain a mystery of the human body.