Hello, basically I woke up with a weird discomfort and a little "ball" on my left arm (actually just above the armpit), but I didn't think too much about it and I went for a little run, (even though it was painful to wear clothing because of this "ball"). While running I felt the discomfort growing and once I went home I saw it red (I really don't remember if I woke up when it was already red or not...) and painful! I cannot even close the arm because of this ball (now huge and red). It's been two days now and today I bought a cream (Hydrokortison CCS 10 mg 1 krem) hoping to reduce it (I thought it was a bite) but no improvements! I don't know what to do, should I worry? I am a 21 years old woman, with deficit in iron and b12 vitamins (I don't know if this can be helpful) and there are no doctors available until Tuesday :( What could it possibly be? something serious or deadly? Thanks for your help, I can be hypochondriacally at the times... sorry for misspells but i am afraid right now :( and I am trying to type fast.