Snakebites are scary to most people, but in a small number of cases, they can also cause really unusual and severe symptoms.
From a ruptured spleen to "reverse puberty," rare effects of venomous snakebites have been reported by researchers over the years.
There are currently more than 3,000 species of snakes in the world; 600 of those are venomous, and more than 200 of these are considered potentially harmful to people because their venom can cause health problems, according to the World Health Organization.
WHO also lists snakebites as one of its 17 "neglected tropical diseases," which are conditions that cause a significant number of illnesses and deaths, but generally get less attention from people in developed countries.
Here is a look at some of the rarest reactions to snakebites.
After an Asian pit viper bit a man in his right foot, the man experienced a spleen rupture, according to a report published in the September issue of the journal Wilderness and Environmental Medicine.
The 60-year-old patient was admitted to a rural hospital in Korea after the snake bit him as he picked pears in an orchard. He was given anti-venom about two hours after he was bitten, but on the third day following the bite, his foot swelled and the pain from the bite worsened, according to the case report. [Image Gallery: Snakes of the World]
His blood's ability to clot was impaired in a condition called coagulopathy, and the man's doctors could not reverse it, even though they administered additional doses of anti-venom.
The following day, the man reported severe abdominal pain. The doctors found that his spleen had ruptured, and they said the blood-clotting issues had likely caused this damage.
"His bleeding was so severe that his spleen ruptured," said Dr. Scott Weinstein, a toxinologist at Women's and Children's Hospital in North Adelaide, Australia, who was not involved in the case report.
The man underwent a complete removal of the spleen, and his condition improved, according to the report. "He was discharged in good health on day 20 after admission," the report said.
In some cases, the bites of venomous snakes called Russell's vipers, which inhabit South and Southeast Asian countries, can cause bleeding in the pituitary gland. This damages the organ and can prevent it from performing its basic function, the production of hormones including those that regulate sexual functioning.
In a report published in October 1987 in the journal The Lancet, researchers examined 33 cases of patients bitten by Russell's vipers. Some of those patients developed serious hormonal abnormalities, which resulted in decreased libido; loss of pubic and armpit hair; erection problems in men; and irregular, scant or absent menstrual periods in women.
This rare side effect may result from the bites of only several specific populations of Russell's viper, which live in four or five geographical spots, Weinstein said. The bad news is that damage from the venom to the pituitary cannot be reversed, he said.
When people develop this reaction from a Russell's viper bite, they need to receive hormone treatments for the rest of their lives or the symptoms will persist, Weinstein told Live Science.
Huge mass in the leg
In some cases, extreme reactions to snakebites can be significantly delayed. In one case, a 66-year-old woman developed a large mass in her left leg more than 50 years after she was bitten by a Malayan pit viper, a venomous snake in Southeast Asia, at age 14, according to a report of her case.
The mass was painless, but had become noticeable when the woman was in her 50s, according to the report published in June 2014 in the Journal of Medical Case Reports.
When doctors X-rayed the mass, they found what looked like an enlarged cavity wrapped in a tough, calcified membrane. [X-ray Image: Mass Caused by a Snakebite]
When the woman returned five years after the X-ray, the doctors found that the mass had become infected and was breaking through the woman's skin, according to the report.
The doctors removed the mass, and the wound healed completely by one month after the surgery.