A closely watched clinical trial in Britain that screened blood for early detection of cancer did not show a reduction in diagnoses at later stages of the disease.

"No cancer signal detected." The blood test results popped up in my online health portal without much fanfare. A doctor would chat about them with me later, congratulating me on the "phew"-worthy ...

Easier than a blood test, saliva tests have the potential to detect cavities, infections and even cancer. But a lack of insurance coverage and other obstacles stand in the way of wider use.

Blood tests are helpful for monitoring your overall health. But research suggests they can also give us clues about the ...