I am not entirely sure they are hemlock trees. They were not doing so hot when I moved in 2015, but it's getting worse over the past few years. They are located near Albany, New York State, US.
Photos are taken on Jun 3rd, 2018. There are growths on all green branches, but the dead branches are looking so dead, and there are branches turning red. The tree might be around 20 years old. Could someone tell the problem based on the photos?