Back pain is not the only type of pain that you are likely to experience during pregnancy, but it is the most prevalent type of pain and for that reason has an entire article dedicated to just its occurrence.
The progression of back pain is one that is logical and follows the development of the baby inside the mother. As the baby continues to develop, it gets bigger. As the baby gets bigger, the mother continues to have her midsection enlarging by larger and larger amounts. As the midsection gets larger, the center of gravity shifts from one part of the body to another. This shift is away from the back and that is where the back pain issue comes from. The gravity center shifts and drags the back down with it, resulting in more pain as time goes on. This is why many women might not experience any back pain during the first two trimesters of their pregnancy and then suddenly feel it shooting through their body during the third trimester. Even though the feelings did not come along until late into the pregnancy, the root cause of the pain were building up the entire time.
Treating the back pain during pregnancy is actually not as difficult as some people might think. There are several small treatments that are low impact and can work to reduce or eliminate the pain. The first is mild exercise in the form of walking. Walking can help alleviate the back pain and getting out and into the fresh air can reduce the pain through eliminating any aspect of it that might be psychosomatic to the pregnancy. Massage is also something that can help with the back pain and it too is a low impact treatment, as is the employment of heating pads to the back in an effort to loosen the muscles and eliminate some of the tension that is likely causing the pain to begin with.