@snoei Funny you ask that, as I sit reading Connect with my morning coffee in hand. I have essential tremor, and my neurologist suggested stopping caffeine a couple years ago. I weaned off and quit, but then a friend who "must" have her 2 morning cups came to stay for a while. I could not resist the lovely aroma, and had my single mug of cafe au lait, then we went for our walk. Without even having used my saline neb or Aerobika, I was coughing up mucus.
So over the next few days, I experimented - as long as I took my Primidone (for the tremor) before breakfast and only had one cup, the coffee loosened the mucus without worsening the teemor. Green tea did not have the same effect. When we were on the road, if I missed my morning coffee, my chest was tight by evening. If I drank a vente form the coffeeshop, my tremor worsens.
Personally, I found my "sweet spot" - one cup of coffee in the morning. I get to keep my 50+ year little vice, I get the caffeine boost, I do have easier airway clearance, and it doesn't worsen my tremor.
Airway clearance is a constant experiment for me - for now, this works.