I have a meyer lemon about 3 years old. Looks pretty healthy buy has quite a few of these twigs of dried up dead wood. Are these a concern or are they normal??? Has lots of setting fruit and new leaves. Cheers

Hard to tell from the picture, but it looks like it could be freeze damage. Just in case it is some sort of pathogen, I would cut off the affected parts of the tree. Be sure to sterilize your pruning shears before and after cutting so you don't spread diseases to other parts of the tree or other trees.

As hydrobell stated it is difficult to to determine from the picture. However, if it is just the small twigs, and not larger branches that have died back, then this is a very common occurrence, not only with Meyer lemons, but for citrus in general. Just cut them out of the tree. Small twig die back is normal and will generally occurs throughout the life of a citrus tree. - Millet (678-)