What would cause urine flow to be weak after waking, but not throughout the rest of the day? my psa count is at the low end of the normal range. could the diaphragm cause this?

Tumescence: Partial erections are not uncommon in the morning and may delay or weaken the urine stream. It is not a symptom of any disorder. Diaphragm is not involved in urination. Have a healthy diet, exercise 30 minutes/day, drink plenty of water, have safe sex, no tobacco alcohol weed or street drugs. For nutrition: http://www.choosemyplate.gov/. Wish you good health!