While most of these links sound strange, knowing about how your body works as a holistic system could pay dividends down the line.
Voice + Height
Researchers from Washington University recently found that listeners can accurately determine the relative heights of speakers just by hearing them talk. Credit the frequency of “subglottal resonance,” a sound produced in the lower airway of the lungs that gets progressively lower as height increases. Ever wonder why your tall buddies talk so low? Now you know.
Eyes + Brain
The small vessels behind your eyes could reveal how healthy your brain is, according to a recent report in Psychological Science. Researchers found that people with wider veins scored worse on IQ tests in middle age, which should give you another reason to get your peepers checked annually.
Skin + Blood Pressure
Wrinkles aren’t just a sign of aging—they could also be a sign of ticker trouble, says a study in the Journals of Gerontology. When researchers separated people into groups based on cardiac disease risk and analyzed the youthfulness of their skin, those with the fewest wrinkles had lower blood pressure and lower heart disease risk.
Pulse + Heart
The flexibility of your aorta may soon be measured by checking the pulse in your finger, according to researchers at the University of Iowa. Your aorta is a major artery that, when stiff, can increase your risk of dying from heart attack or stroke.
Hands + A Man’s Package
Men whose index fingers are shorter than their ring fingers tend to have bigger penises, according to Korean studies. It has something to do with testosterone levels in the womb, which control both penis and finger lengths, the researchers say.
Fingers + Cancer Risk
While a longer index finger might give you the…er, short end of the stick, here’s one plus to a big pointer: It could put you at a lower risk of prostate cancer, according to a study in the British Journal of Cancer. Having less testosterone in the womb might help keep prostate cancer at bay later in life.
Teeth + Mind
A study in the Journal of American Geriatrics suggested your ability to chew might predict your risk of dementia. But don’t get too worried if you have trouble chomping: The researchers don’t know if mental decline leads to poor dental care and less bite force, if difficulty chewing impacts the brain, or if it’s simply just a random correlation.
Sleep + Eyes
People with sleep apnea are almost twice as likely to develop glaucoma—an eye disease that can lead to blindness—within five years, finds research from Taiwan. When you aren’t breathing at a normal rate, the loss of oxygen triggers damage to the optic nerves or causes abnormal levels of gases in your blood—both of which could lead to glaucoma.
Lips + Memory
That pesky outbreak on your lip (don’t worry, you’re one of millions who get cold sores) could put you at an increased risk for Alzheimer’s and dementia, according to a study at Columbia University. Researchers followed adults between the ages of 59 and 79 for eight years and found that those with a higher infectious burden—meaning they’d been exposed to a higher-risk virus, such as herpes simplex virus 1 and 2—were more likely to have poorer cognition.
Legs + Erection
Suffering from restless leg syndrome (RLS)? You may have more serious problems than a case of the jimmy legs, finds a recent study from Harvard Medical School. Researchers found that men who had at least five RLS episodes each month were 50 percent more likely to develop erectile dysfunction than guys without fidgety limbs. Both conditions are linked to low levels of the feel-good chemical dopamine, which might be one potential explanation.
This article originally appeared on Men’s Health.