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.
There are various causes of left side pain in the left abdominal area and the following are a list of the most common causes: 1  Food poisoning. Consuming contaminated food can lead to food poisoning. This can result in vomiting and fever as well as severe pain in the left side to the abdomen. 2  Constipation.