If desire is the causation of suffering, isn't all of life desire? When we are hungry we desire food. When tired we desire sleep. How do we banish these desires without dying or losing our minds?

Yes, you are right, all of that is driven by desire. There are three bases of desire: lobha (greed), dosa (aversion), and moha (delusion). Desire within these three bases is acknowledged as the causation of suffering. When you are hungry, it is okay to eat in the motivation of fulfilling daily nutrition necessity for doing the right effort. Do not eat more than you need because it gains greed (lobha). It's okay for you to desire to be free from these three bases, it's called right effort. To understand more, read about Four Noble Truths and Noble Eightfold Path. It is also okay to read some Dhammapada verse.