It's due to the increased production of Melanin that helps block UV light
Plasma is the liquid component of blood, in which the red blood cells, white blood cells, and platelets are suspended. It constitutes more than half of the blood's volume and consists mostly of water that contains dissolved salts (electrolytes) and proteins.
It depends on the indicator type; typically if it is darker in some way, it is positive
You could take deep breaths and attempt to solve the problem yourself. You could also talk to someone who has dealt with similar problems in which they can help you solve your's. If that doesn't work, you could talk to your doctor about your stress so that he could prescribe you with a medication or a healthy lifestyle to help you with your stress.
