I put myself on a baby aspirin because I refuse to take the blood thinner and the side effects, which the doctor said WHAT SIDE EFFECTS? I said BLEEDING! I may not even need this aspirin, but need to lose weight and older people who have an infection can get thick blood. It has to do with proteins in the blood, and your immune system sort of over reacting to the infection. Probably everybody has this with an infection but older people have more trouble because of the other things of sitting, dehydration. I read of reports where older people going to ER with unexplained pulmonary embolism were found to have had an infection within 3 months of the clotting event, which I did with the chickenpox, 2 months and then last year upper respiratory virus and within 2 months had another pulmonary embolism. You have to be active, but really that’s not what does it, you get dehydrated, cold, stressed, and your blood is thick like sludge. I think there is a misunderstanding of clot and sludge. I did not have A clot, I had what they called clot burden in both lungs. Your lungs are like filters and I think I had a little sludge, and a little more, until I had symptoms and people may have this on and off and not even know it until it is bad.