10 Diseases Doctors Miss

Like Joyce Dixon, millions of Americans spend years suffering from unexplained health problems. Here, some of the diseases most often missed:

HEART DISEASE Coronary heart disease, the leading cause of heart attacks, is America's No. 1 killer. Women are less likely to be diagnosed, mainly because their symptoms can be different from men's, such as unexplained fatigue, trouble sleeping, and lower chest or abdominal pressure, which can be mistaken for heartburn, chronic fatigue or anxiety.

CHRONIC OBSTRUCTIVE PULMONARY DISEASE COPD, which covers chronic bronchitis and emphysema, is the fourth highest cause of death in the United States. COPD is often misdiagnosed and undertreated as asthma.

HEPATITIS C It's the leading cause of liver transplants and the most common cause of liver-related deaths in this country, but as many as 70 percent of those infected are unaware they carry the virus.

SLEEP APNEA If you've been told you're a loud snorer at night or you can't explain why you feel so tired during the day, you may have obstructive sleep apnea, which can significantly increase the risk of stroke or death.

CHLAMYDIA Almost 3 million Americans a year get this sexually transmitted disease, yet most cases are not reported because of lack of symptoms. Chlamydia can damage reproductive organs and cause infertility and chronic pelvic pain in women.

HEMOCHROMATOSIS This overload of iron in the body can lead to liver or heart failure, Diabetes, even death. Symptoms include fatigue, joint pain and loss of sex drive.

CELIAC DISEASE In adults it takes an average of 11 years to diagnose celiac disease, a genetic autoimmune disorder in which sufferers can't digest gluten, a protein in wheat, rye and barley. An estimated two million Americans have the disease but an astounding 97 percent go undiagnosed.

LYME DISEASE Spread via deer ticks, this infection enters the bloodstream and can cause symptoms (chills, fever, body aches) that many doctors write off as the flu. It can lead to arthritis and nerve problems.

HYPOTHYROIDISM About half of the nearly 27 million people with an underactive thyroid are undiagnosed. Symptoms such as fatigue, weight gain, hair loss and poor memory are often dismissed as normal signs of aging.

LUPUS This autoimmune disease, found mainly in women, can cause common symptoms such as fatigue, achy or swollen joints and fevers. More than half say they suffered for at least four years and saw three or more doctors before getting a diagnosis.