should I code HTN or not...?

Hi I am a new coder and I am very confusing about coding HTN and I really need experienced coders like you.

When I see doctor's document(inpatient, established note),

often it looks like following,

pt name ooo
03/05/15 12:30

vital: 120/80 3/5/15 0830
cv:blah blah blah
pulm: (I will omit these things)

A/P: Pt has htn... blah blah....

In the above case, can I code htn?
(doctor check vital 8:30 in the morning and this document was written 12:30. Then, it looks like
I have to code HTN(because at 8:30 blood pressure was normal but at 12:30, pt became HTN.)

However, someone I know said that "even if doctor said HTN, since the number is 120/80, you shouldn't code HTN.

Which is right...?


Please teach me about it.
(Please answer those who has been coding for a long time. no offense. I just need to know accurately.)
Thank you so much

yuna