Tea has caffeine in it which can lead to irritability, increased heart rate, increased blood pressure, and sleeplessness. Tea also contains another substance (I think it is called theophelin) causes a 'thickening' of mucous membranes which (in turn) can (amoung other things) lead to sinus headaches, sinus infections, and constipation.
Tea has caffeine in it which can lead to irritability, increased heart rate, increased blood pressure, and sleeplessness. Tea also contains another substance (I think it is called theophelin) causes a 'thickening' of mucous membranes which (in turn) can (amoung other things) lead to sinus headaches, sinus infections, and constipation.