Yes , long hours, days, weeks of sitting at a desk or a similar postures (head, shoulders, arms forward ) tends to stagnate the body fluids.
It's called static postures - as there is not much motion happening.

Getting up and moving around often with gentle ROM motions and even some reverse postures will help to offset the ill effects.

If you can get or change your job to something with more mobility and movement you will be much better off.