Good Morning,
It is hard to tell by the photo.  You may have more than one problem.  I suggest having an arborist come out and assess the tree. TreesAreGood.org

For some disease issues, such as needlecasts, fungicides may be effective in preventing or controlling the disease. It is important to note that fungicide treatments for needlecasts only protect new growth. For control to be fully successful, it may take two to three years of yearly fungicide applications. For canker diseases, the effectiveness of fungicides is usually limited. Removing affected branches is usually the best action to improve the tree’s appearance and slow the spread of disease within the tree.
For insect or mite issues, insecticides or miticides can be effective, however selection of the proper product and timing are critical.

You can also send in a sample to get a firm diagnosis.  Plant & Pest Diagnostics (msu.edu)

What is spruce decline and what should you do about it? - Christmas Trees (msu.edu)

I hope this helps.  Thanks for using our service.