Ducharme is a contributor to TIME. Technician preparing human medical samples for screening in the lab. Ducharme is a contributor to TIME. How much protection do you currently have against COVID-19?

Vitamin B12 is vital for good health. Your body needs steady levels of this nutrient to make enough red blood cells and keep your nervous system working. If you eat a balanced diet, you’re probably ...

What Is an Arterial Blood Gas Test (ABG)? An arterial blood gas (ABG) test measures oxygen and carbon dioxide levels in your blood. It also measures your body’s acid-base (pH) level, which is usually ...

A refraction test is usually given as part of a routine eye examination. It may also be called a vision test. This test tells your eye doctor exactly what prescription you need in your glasses or ...