From the colour of our hair and eyes to the size of our chest and fingers, how we look can say a lot about our health.
Here we highlight the ways our features can say things about our wellbeing.
If your earlobe has a crease, it may mean you have a dodgy heart.
Studies suggest a wrinkle there can put you at a higher risk of heart disease or a stroke.
It is thought the crease shows that blood flow through the small vessels to the ears is weaker, possibly linked to a build-up of plaque in the arteries.
This makes the skin less elastic.
The colour of your hair can suggest something more sinister.
Redheads are at a higher risk of skin cancer and have a lower pain threshold.
But gingers have also been shown to have a lower chance of prostate cancer.
And the idea of a “dumb blond” is nonsense – blonds have, on average, slightly higher IQs than the dark-haired, suggests a study by Ohio State University.
One in ten of us are left handed, and experts reckon lefties are twice as likely to suffer from bowel disease. But they have lower rates of arthritis.
Left-handers are more likely to drink alcohol and get depressed, but they recover faster from strokes.
Having blue, green or grey eyes and fair skin puts you at greater risk of eye cancer, a US study says.
But blue eyes was linked to a lower risk of developing the skin condition vitiligo.
A study by the University of Louisville found people with brown eyes have quicker reaction times and tend to get drunk faster.
Having a big conk could stop you getting ill.
Researchers at the University of Iowa found bigger noses inhale fewer pollutants, deflect germs from the mouth and can reduce hay fever effects.
Blokes who look macho, with square jaws and wider faces, have lower sperm quality, says a study in the Journal of Evolutionary Biology.
Research shows women with larger chins tend to be more sexually active, perhaps because of higher testosterone levels.
Does size matter?
Men with a larger penis had better general health, researchers in Australia found.
Shape might be important too.
A study by Baylor College of Medicine in Texas found blokes with a crooked penis are at a higher risk of developing several types of cancer.
A study in journal BMC Medical Genetics found women with bigger busts are more likely to have genes linked to breast cancer.
Another from Chicago University suggested that women with larger breasts are smarter.
In men, a ring finger longer than the index finger on the right hand indicates a high sex drive, say scientists.
But those with longer index fingers than ring fingers have a third less chance of prostate cancer.
Shorter legs have been linked to a higher risk of type 2 diabetes and dementia but a lower risk of fractures in older age.
A study from Denmark suggested people with chunky thighs have less chance of heart disease or dying prematurely.
People with short toes are better at running, while those with long toes will suffer more injuries, such as tendonitis.