When we talk about tone of voice, what we really mean is how you make the reader feel.
The words you use and the order you put them in can make a reader feel warm or scared.
When a reader searches for help or information on a health topic, they may be worried or stressed.
I think our job is to present information in a way that helps, encourages and is compassionate.
Give the reader a reason to keep reading by helping them feel better through our choice of words.
At the very least, offer solutions and a positive mindset as the answers to their problems.