In medicine, a person’s blood-test results are compared with the average range in a population. But results are highly individual and tightly regulated around a person’s own stable values. Changes to ...

Your doctor says everything looks fine, but you still feel terrible. The problem might not be your health but how labs define “normal.” Understanding the difference between normal and optimal could ...

A blood test comes back showing vitamin B12 in the normal range, and the conversation moves on. But for older adults, that ...

DEAR DOCTOR K: Last week I received the results of some recent blood work. A few of my values fell just outside the normal range. My doctor says it’s fine, but I’m still worried. Do I need to be? DEAR ...