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This could be a frictional injury due to tight laces making the shoes rub against the skin. Once this heals, and you will need to give your foot some rest, you should be fine. Maybe in the long run you will either have to change the shoes, or wear a padding below the laces.
The other possibility is an infection. It can also be a nerve compression or a tendon injury.
Please consult your PCP for primary examination followed by proper referral, preferably to a sports medicine specialist.
u shuld stop running until ur lump has gone otherwise it will become bad and it will cause pain.....and go to a doctor and take sum medicines
u can ask me on twitter too and medhelp both,my twitter id is sid850
Walk or stroll first then when you are healthy enough run.
Went to see my physio who diagnosed as Tenosynovitis. Taking NSAID and staying away from downhill running for a bit as that's where I feel most discomfort