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Got a health issue? You might be in line for another. "The body is interconnected, so when one system is not functioning, it affects all other systems," says cardiologist Suzanne Steinbaum, MD, director of Women's Heart Health of Lenox Hill Hospital in New York City. A perfect example: In diabetes, a glut of sugar and insulin in the body causes inflammation, which then damages your artery lining, allowing plaque to build up. This process eventually increases your risk of heart attacks and strokes. So although diabetes is initially a problem of high blood sugar, it can ultimately lead to heart disease.

Here, other diseases you might be surprised to learn are linked:

Celiac Disease + Thyroid Issues
About one in 100 people around the world have celiac disease—an autoimmune disorder in which the ingestion of gluten (a protein found in wheat, rye, and barley) leads to damage of the small intestine. Not only must celiac sufferers resist bread and most baked goods, they're also more likely to develop problems with their thyroid, the gland that pumps out hormones influencing metabolism, growth, development, and body temperature. A 2008 study found that people with celiac had nearly three times the risk of hyperthyroidism and four-and-a-half times the risk of hypothyroidism compared to people without celiac. Italian scientists investigating the connection believe that undiagnosed and untreated celiac may flip a switch in the body that sets off a cascade of other disorders. If you have one of these disorders, do yourself a favor and get tested for the other. In either case, a gluten-free diet will help you manage symptoms.

MORE: 5 Myths About Going Gluten-Free That Really Need To Go Away

Heart Failure + Osteoporosis
Heart trouble can weaken your skeleton. A 2012 study linked heart failure to thinning of bones and a 30% increased risk of major fractures. The exact mechanisms are still unclear, but there are several theories. One possible explanation is that common genes impact both conditions. Another theory involves circulation: When clogged arteries hamper blood flow to the lower extremities, the traffic of minerals between the blood and bone tissue plunges. If you've had trouble with your heart, seek out a bone mineral density test. And next time you're in for a chest X-ray, ask your doctor to look carefully for signs of fractures. If any are found, you'll want to increase your intake of calcium and vitamin D, boost your exercise, and consider osteoporosis medications. Doctors say treatment can reduce future fractures by as much as 50%.

MORE: Is Your Heart Older Than You Are?

Psoriasis + Psoriatic Arthritis

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You likely already know if you have psoriasis—an autoimmune disease that causes raised, red, scaly patches usually on the outside of the elbows, knees, or scalp. What you probably don't know is that one in five sufferers—about 7.5 million Americans, or 2.2% of the population—also goes on to develop psoriatic arthritis, according to the National Psoriasis Foundation. Psoriatic arthritis causes painful joint inflammation—with sore, stiff, and tender joints—and can lead to irreversible joint damage if left untreated. Experts estimate that some 50% of cases are undiagnosed. If you have psoriasis, ask your doctor to screen you for psoriatic arthritis—as well as rheumatoid arthritis and even increased risk for stroke and heart attack, which have also been linked to the disorder.

Diabetes + Depression
Having diabetes, which affects 16 million Americans, more than doubles your risk of depression, studies show. The tremendous stress of having diabetes—with symptoms such as fatigue, nausea, frequent urination or infections, unusual thirst, blurred vision and slow wound healing—may be enough to trigger the blues, but it's also possible that depression results from the metabolic effects that diabetes has on the brain. Diabetics may also have symptoms that look like depression: Blood sugar swings can leave them feeling tired and anxious; the swings can also interfere with sleep and encourage overeating. People with diabetes should keep the lines of communication open with their doctor and don't hesitate to seek out the services of a mental health provider.

MORE: 6 Natural Depression Remedies Worth Trying

Pneumonia + Cardiovascular Disease
If you've been hospitalized for pneumonia, your risk for heart attack and stroke jumps significantly in the following weeks and months—in fact, for up to 10 years, according to a January 2015 study in the Journal of the American Medical Association. Although research has linked the two issues before, this study was the first to look specifically at people who had no signs of cardiovascular disease before getting sick. The researchers are now suggesting that pneumonia be considered an independent risk factor for cardiovascular disease.

COPD + Shingles
What do lung disease and chicken pox have in common? Having one doubles your risk for the other. Not chicken pox, exactly, but shingles (herpes zoster)—a painful skin rash caused by the same virus. A 2011 study in the Canadian Medical Association Journal found that people with chronic obstructive pulmonary disease (COPD), a lung disorder involving blocked airways (from chronic bronchitis or emphysema, for example) were more likely to develop shingles, especially if they took oral steroids. It's well known that shingles tend to strike when the immune system is compromised, and there is increasing evidence that COPD is an autoimmune disease. If you have any chronic lung disorders, talk to your doctor about whether the herpes zoster vaccine would help you.

Hot Flashes + Bone Density Problems
As if the hassle of hot flashes and night sweats during menopause wasn't enough: These symptoms may point to another issue—low bone mineral density. A study in the January 2015 Journal of Clinical Endocrinology & Metabolism found that women who experienced significant menopausal symptoms went on to have double the rate of hip fracture compared to women who weathered menopause without symptoms. The researchers don't yet know why having hot flashes speeds bone loss, but they're encouraging women who are at greater risk to take steps to protect their bones—by ramping up the exercise and making sure to get enough calcium and vitamin D.

MORE: 8 Highly Effective Ways To Make Menopause Less Miserable