Life does not stop because of small obstacles, and neither should we. The secret is to deal with them and keep moving forward.
A cyst on the upper arm is a small obstacle that many people ignore for a long time, because it usually does not hurt at first.
Like cysts elsewhere on the body, it forms when skin cells get trapped under the surface and keep producing keratin inside a sac.
The upper arm is exposed to constant movement and friction from sleeves, so a cyst there can become irritated and inflamed fairly easily.
When that happens the lump turns red and sore, and simple everyday movements such as lifting a bag or putting on a shirt become uncomfortable.
