As Dr Taufiq explained, going to see your GP for an interpretation of the results would be a good first port of call. This is because there are many causes for abnormal blood tests, which need to be interpreted in the context of other factors (eg. any other existing medical conditions, health issues, etc).
For example, reactive thrombocythemia is one of the most common causes of high platelet count. This can be attributable to infection, tissue damage, inflammation, iron deficiency, medication etc.
If necessary, your GP can direct you to the appropriate specialist after analysing your blood report. There are again many specialists who deal with abnormalities of blood test lab results, ranging from Haematologists to Internal Medicine Doctors, so it's really difficult to advice your based on just an abnormal platelet count reading.
