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.
If a large stone forms in the left kidney, it can cause sharp and cramping pain on that side of the abdomen, usually in the lower quadrant. The pain may also be felt in the left mid-back, side and groin. Accompanying symptoms may be nausea, vomiting, blood in the urine and pain with urination.