What causea a thick green vaginal discharge with no smell and no itching?

Needs Evaluation. Certain types of discharge is more "normal" than others. Clear discharge without odor may simply be hormone related. However, yellow-greenish discharge should always be investigated. It is not necessarily an std, as yeast may present similarly. Nonetheless, you will like to have an exam to test it to treat it correctly. Contact a local gyn office. The exam is fast and painless.