This infection may increase post-nasal drip. If you suspect that you have a sinus infection, you should see your physician to see if it needs antibiotic treatment. Chronic sinusitis occurs when sinus blockages persist, causing the lining of the sinuses to swell further.
Causes of Pain in Left Side Back. 1  Pregnancy: Back pain especially on the left side, is very common in pregnancy and happens for a few reasons. As the child develops in size, the uterus can pack torment delicate structures including nerves. 2  Kidney Infection: Kidney diseases can cause left side back pain.
Bottom Line: You can also experience leg pain, arm pain, head pain in left side. Different types of reasons are responsible for left side pain. Home treatment can give you comfort for a short time, however, you need to talk to your doctor as pain in left side can be the indication of some serious diseases.