Are you more likely to develop stomach ulcers or asthma? Have issues with your thyroid or your heart? Osteoarthritis or osteoporosis? You may be surprised to learn that your propensity toward certainty diseases may have a lot to do with the month in which you were born.

In a new study, researchers from Spain showed that a person's birth month may be linked to the chronic diseases that show up later in life. Researchers looked for patterns between the birth months of 30,000 study participants and the risk of 27 chronic diseases, and they were surprised by how closely the two were linked. For instance, they found that men born in September were three times as likely to suffer from thyroid issues as men who had a January birth date while women born in July were 27 percent more likely to develop high blood pressure than women born in any other month.

The team also uncovered some good news — like the fact that men born in June are 34 percent less likely to develop depression and women born in the same month are 33 percent less likely to suffer from migraines.

Why the link between birth month and chronic disease? That's one issue the researchers didn't resolve. It's possible that seasonal variations in daylight, sunshine and illness may impact the health of babies at critical points in their development. This might explain why September babies — both boys and girls — are the healthiest of all of their peers (after absorbing all of that summer sun and vitamin D in the womb.)

Want to know which chronic disease the future holds in store for you? Here's the likelihood, according to your birth month:

Winter baby Constipation may be a regular issues for men born in January. (Photo: My Good Images/Shutterstock)


Men: Constipation, stomach ulcers and low back pain

Women: Migraine, menopause issues and heart attack


Men: Thyroid issues, heart conditions, osteoarthritis

Women: Osteoarthritis, thyroid issues, blood clots


Men: Cataracts, heart conditions, asthma

Women: Arthritis, rheumatism, constipation


Men: Asthma, osteoporosis, thyroid issues

Women: Osteoporosis, tumors, bronchitis

Baby with spring flowers Little girls born in May are most likely to develop chronic allergies later in life. (Photo: Olyshko Mykhaylo/Shutterstock)


Men: Depression, asthma, diabetes

Women: Allergies, osteoporosis, constipation


Men: Hearth conditions, cataracts, bronchitis

Women: Incontinence, arthritis, rheumatism

Summer baby Men born in July may be more likely to deal with asthma later in life. (Photo: Katrina Elena/Shutterstock)


Men: Arthritis, asthma, tumors

Women: Neck pain, asthma, tumors


Men: Asthma, osteoporosis, thyroid issues

Women: Blood clots, arthritis, rheumatism


September baby September babies are the healthiest babies. (Photo: Andrei Mayatnik/Shutterstock)

Men: Thyroid issues, osteoporosis, asthma

Women: Thyroid, osteoporosis, malignant tumors


Men: Thyroid issues, osteoporosis, migraines

Women: High cholesterol, osteoporosis, anemia


Men: Chronic skin issues, osteoporosis, thyroid issues

Women: Constipation, heart attack, varicose veins


Men: Cataracts, depression, heart issues

Women: Bronchitis, asthma, blood clots

There's a link between your birth month and certain diseases
Seasonal variations in levels of daylight and illness might explain the variation, but doctors will need to do more research.