I am female, 52, 5 8 ,160 lbs and in good health. I am regulary treated for PTSD, anxiety and depression. I have been extremely tired. My thyroid shows on the low side of normal. The Dr. upped the Liothyronine from 10 to 15mcg in the last four weeks. I take Buspirone 5mg 2 X daily, Sertraline 50mg 1 X daily, Ropinirole 1mg in the pm, Gabapentin 600-900mg in the pm, Venlafaxine 75mg in the am, Estradiol 1mg in the am, Progesterone 100mg 12 days out of a month, Liothyronine 15mcg 2 X daily. I often get a kidney infection. I have to be really carefull with soda. I have had a kidney infection this week and started taking ciprofloxacin yesterday. This morning I woke up with a 10 inch long bruise on my under arm, from my arm pit to my elbow bend. It s extremely sore when I stretch my arm out and is achey. I don t notice any other bruises. I have a sit down job and I have not done anything physical for days. What can cause unexplained bruising?