Our skin is acidic around a 5 on the Ph scale. This is to fight off unfriendly bacteria like Propionibacterium acnes. This is where acne got it's namesake. If you wash your face with soap which is very alkaline, ususally a 10 ph, then you are setting yourself up for a breakout. If your cleanser is too acidic you will usually have dry, red, sensitive skin. The solution is to always use products that say on the bottle that they are ph balanced. Otherwise the only way to find out is to do a little research on your own. Call the 800 phone number off of the packaging (usually only found on the box) and ask them what their ph is of that particular product. It needs to be a 4.5-5.5 range or don't get it.
Also, it takes 24 hrs for your skin to get back to a normal acidic ph 5 after you use a bad product. If it is used morning and night your skin doesn't have a chance. I have seen many many women who are having troubles with their skin that have corrected it simply by switching a cleanser or cream. I really believe ph is extremely important to perfect looking, beautiful skin. If you do have a product with a bad ph and move over to a ph balanced product make sure to give it a fair shot. It takes typically 2 months for skin to completely come around, but it is so worth it. If this helps even one person out there I am happy. Tell me how it goes. All the best.