Unless you know someone who has primary immunodeficiency (PI) or you are that someone, you probably haven't heard of it. To a large extent, the clue is in the name: people with PI have deficient immune systems.
Fortunately, there are treatments available and measures people can take to prevent complications, although there is currently no cure. Thankfully, the majority of primary immunodeficiencies are rare, although this also means awareness is generally low.
With this in mind, check out the following gallery to learn all about primary immunodeficiency and why it occurs. Click on for more.