Help!! what does reddish stem mean?

I have a plant that's in the 4th week of flowering and the main stem is turning a reddish violet color in some areas... is this bad and how do i fix it ????

Pics would be sweet ! My personal opinion is this, if there happy and leafs seem cool with no sigh's of deficiency or any other problems, then go with it and be well I have seen many strains get reddish or maroon stems. Some deficiency's can cause ur problem but A LOT of them are from strain. So how does the rest of it look