Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. I would like to clarify whether you mean left side of your throat or left side of your neck. In the former case, start with steam inhalation and warm saline gargles four times a day. If symptoms persist or a new symptom develops, let us know for further treatment. In the latter case, there is probably a neuromuscular component like trapezitis or cervical spondylosis. In this situation, I would recommend a X-ray of cervical spine AP and lateral. Meanwhile, try hot fomentation (set temperature well below your maximum tolerable limit). And avoid looking downward. Let us know when you get the report of the x ray. Best wishes.