Ideas to deal with table corruption

Dear community,

I am looking for ideas, to help me, check what is happening with a
possible table corruption, I have some FK that works ok, but some stay in
the state waiting forever, however selecting the same table works fine.

Since, I am a newbie, in PostgreSQL, what should be my firsts steps, in
order to have an idea how to fix this problem.

I am thinking in watching my postgresql log error file during the requests
for creating our FK,
What do you suggest me

Centos 7.2
Postgresql 9.4

Thanks