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Since you have back pain and unexplained bruises, rheumatoid arthritis and ankylosing spondylitis should be ruled out first.
If you are not on any medications like anticoagulants, or blood thinners then this could be due to clotting disorders, low platelet count, fragile spider veins, deep vein thrombus, deficiency of Vitamin B12, folic acid, or Vit K, a liver disease or certain cancers. It could also be due to pressure urticaria. If you are on medications then you need to discuss that with your doctor.
A lump in breast should be further investigated.
Do discuss this with your doctor and get yourself examined. Take care!
get your kidney checked, it can be a kidney infection.