Random sore spot on upper arm by shoulder.no discoloration or warmth but if touched,hurts.looks normal,little swollen.very randomly appeared.ideas?

Soreness: If there is no recent injury like a sprain to explain your symptoms, it's possible that the problem is tendonitis especially if shoulder motions produce pain. I recommend a trial of cold alternating with warm applications and,if you can take them, anti-inflammatory medications like Advil or Aleve(with food). If symptoms persist or worsen see your physician or an orthopedic specialist.