I'm guessing, but I expect the doctors will tell you that you have inflammation in the knee, and they'll prescribe bags of anti-inflammatory pills for (X,000) or (XX,000) Baht. There are numerous natural foods (incl. fruits and berries) that reduce inflammation effectively. If you eat western-style foods, they will probably be one of the causes of the inflammation, if that is what you have. The doctors will probably also give you many other pills, such as antibiotics, which will destroy your body's main immune system, the gut microbiome. Antibiotics are good at doing this. Lastly, are you overweight or an active runner? I wish you a speedy recovery.