You are probably having some kind of Magnesium and/or Iron deficiency. Chelated Iron and Epsom Salt will help you.

For Chelated Iron, I use http://www.amazon.com/Grow-More-7451-2-Pound-Organic/dp/B004G1GDK0 . It works for me.

For Epsom Salt, go to your nearest CVS, Walgreens etc and get a box.

Good luck.

I wouldn't be in too much of a hurry to start applying this & that with nothing more than the hope it's going to cure an undiagnosed 'something'. Iron deficiencies in containerized plants are usually pH related, and Mg deficiencies rarely occur until the second or third year a plant has been in the same (commercially prepared) potting soil. Applications aimed at supplying only one or two elements essential to growth are more often limiting than beneficial.

My guess is that your plant hasn't been repotted in a long while and root restriction is the likely culprit, which also explains why the plant is exhibiting chlorosis on one side only. Is foliage also primarily concentrated near apices (growing branch tips)?

Have you been using a fertilizer with a middle number higher than the others? - what fertilizer are you using? Have you ever repotted, as opposed to only potting up?

Al