In 2018, I had what I thought was just a sore knee from all the walking I did looking for downed power lines after a hurricane. I went and bought a Copper Fit knee brace and wore it for a few days. Knee quit hurting, but I had a cramp in my calf now. Long story short, it ended up being a DVT (Deep Vein Thrombosis). I was on blood thinner for a month or so and haven't had another since. While I had the DVT, I also had a dry cough that came from my chest. The ER Doc said that your body will naturally try to break up a clot. Veins feed the lungs, so any small clot pieces that the body breaks up go to your lungs and the lungs sense a foreign object and trigger a slight cough to try to make it exit the lung. Clots in veins go to your lungs. Clots in arteries go through your heart or brain and usually cause instant lights out!