To most of us, the immune system is a mysterious and complex network of cells, receptors, and messengers that we only notice when it goes awry. But our immune response, or lack of, affects nearly every aspect of our bodies and our health. Much has been made of 'boosting' immunity, but what exactly does that mean? And what if boosting isn't really what our immune systems need?

In The Immunotype Breakthrough, functional medicine doctor and immunity specialist Dr Heather Moday explains that, for the most part, what our immune systems truly need is not boosting, but balancing. She identifies four distinct immunotypes, and helps you find yours:

Smouldering: too much inflammation, resulting in diabetes, dementia, heart disease

Misguided: an immune system which attacks your own cells and organs, causing autoimmune diseases

Hyperactive: overreactive to harmless substances, causing allergies

Weak: an immune system that doesn't react fa