8.0 pH in the first morning urine signifies that ammonia is present in your urine. Basically ammonia makes the urine pH hyper-alkaline. The reason that ammonia is there is to buffer out a high degree of hydrogen ions. (which are the basis of acidity)
If you didn't have the ammonia buffer, your urinary tract mucous membranes would be burned away by the acids.
There is a way of confirming this. Nesslers reagent is this method. You can read about it here:
Many people with 8.0 pH falsely believe that they have an alkaline tissue pH. In reality, nothing could be further from the truth. This means that you are in a state of emergency acidosis.
IMPORTANT NOTE: If your pH is 8.0 after a meal, this is a normal thing and does not signify acidosis. (due to the alkaline flood from the meal) The 8.0 pH and emergency acidosis connection only applies for the first morning pH.
Finally, urine pH can be incorrect with some pharmaceutical drugs. If you are on meds, then urinary pH might not be that accurate.
You need to take action immediately and figure out this situation. Basically, your tissues and organs are crying for minerals and oxygen right now. Also, it is highly probably that you have a hidden infection somewhere. (quite possibly in the mouth)