Do we need "the" in this sentence? (definite article)
Hi friends

Which one is the correct sentence & why? (wound or the wound)

1. Pain is pain regardless of the size of wound.

2. Pain is pain regardless of the size of the wound.

Thanks & best regards
Niwantha

The second is correct.  

In general you should use an article, definite or indefinite, after a preposition. In this case your use of the definite article is perfect.