The following information is from Gransfors Bruk.
Axes should be kept in a dry place, but not so dry or warm that the handle risks shrinking in the axe head. Make sure that the bit and the bit sheath are not wet when you put on the sheath. Oil the axe head before the axe is put away for some time. An un-oiled axe may rust.
Axe heads are forged for cutting or carving. Only the poll of a Splitting Maul is strong enough for hammering in a wedge, for example. Do not use other axes as a sledgehammer or wedge. If you hammer too hard on or with an axe, the eye of the axe may deform or break.
An axe handle, whether fixed with a wedge or glue, may come loose if the axe has been fitted with a handle that has not been dried properly*. Check regularly that the axe handle is secure in the axe head.