pocketnico saidIt's probably a sebaceous cyst if it's behind the ear and fairly hard. Those cysts are quite common and often appear in the earlobe or just behind the ear (though they can appear elsewhere on the body too).
I have a cyst in my earlobe that flares up a few times a year. It goes away on its own as long as I don't mess with it.
They're nothing to worry about as long as you don't pick at them, otherwise you might run the risk of an infection. Should the cyst grow exceptionally big and start to cause pain, then you might want to see a doctor about it.
I'd tend to agree with this 'diagnosis.'
Or it's AIDS. Duh. Everybody's got it.
No but srsly- I develop this weird cyst on the side of my nose when I get stressed or anxious about something. It's only happened 3 times in the past 4 years, but it's always in EXACTLY the same spot. Just don't pick at it etc. Fortunately if it's behind your ear it should be pretty hidden, and not like mine which was a giant red lump on my face. Pretty embarrassing. Warm to hot compresses might help the swelling go down. I used to boil water, dip a face cloth in it and just when it was cool enough to touch I'd hold it in my face. Apparently it can help draw blood to the area or open the capillaries to help flush out any toxins or bacteria in the area.