Tachycardia or high pulse rate can be due to low BP, anemia, hyperthyroidism, fever, low blood sugar, anxiety and panic disorder, heart causes like sinus tachycardia and palpitations,
alcohol, coffee, effect
of certain drugs etc.
Though it is very difficult to diagnose a lump without examination, I will try my best to list the possibilities and explain how each lump is diagnosed. In some people the occipital bone at the back of the skull has a protuberance. This is a normal finding.