"Shadow diseases" that strike togetherExperts aren't sure why some illnesses travel in pairs, but knowing your risk will help you stay safe.
For years, doctors have observed that patients with one illness may be stricken by another condition that's seemingly unrelated and sometimes more serious, known as a "shadow disease." One of the most well-known is the connection between migraines and heart attack or stroke. Now researchers are uncovering even more linked ailments and zeroing in on why they appear to travel in pairs.
Studies show that these couplings occur for different reasons. In some cases, one disease creates damage that causes the second illness. In others, troublesome genes or poor health behaviors, such as smoking or lack of exercise, trigger one problem, then the other. Being alert to the following dangerous connections can help you avoid the shadow disease or get early diagnosis and treatment, leading to a better outcome.