<s>[INST] I have just last week had my doseage of Citalopram increased from 20 to 30 MG. Today I have started with a severe pain in the left side of my head behind my ear as well as a cold, tingling sensation that speads over my head as well as my head being numb to the touch. i also feel quite nauseous.What coud this be????? [/INST] Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. The symptoms that you described here, (Headache, numbness, cold and tingling sensation of headache) may not be due to any disease but it seems to be due to some functional disorders as you are already taking the antidepressant medicine so try to come out of the stress, be positive, if the symptoms persist for days then better to get done the CT of head. Hope I have answered your query. Let me know if I can assist you further. </s>