Mrs. Kennedy, a 43 year-old female, presented to your office complaining of right sided low back pain. It radiates into the right posterior knee but never into the calf or foot. This pain started approximately 4 weeks prior to presentation while shoveling 6 feet of snow. She stated that the pain was a 6/10 on a numeric rating scale (NRS). It was described initially as an ache that becomes sharp when she goes up steps and from sitting to standing. Ice and Tylenol helps temporary. She went on to state that she has been sitting in a hot tub for 20 minutes a day, which makes it feel better only for about 30 minutes. Mrs. Kennedy went on to state that she has other symptoms that she does not know what is causing them but would like your advice and recommendations.  Current secondary symptoms consist of: Shortness of breath, feeling weak, irritable and fatigued easily. She also has noticed slight blood in her urine, and a yellow cast on her skin. 

Significant Social and Medical History: Mrs. Kennedy has been diagnosed with systemic lupus but has been in remission for six months.

Social history: She leads a sedentary lifestyle as an office worker. She is a non-smoker, non-drinker. She complains of stress from work and her family. Her breakfast consists of 1 poached egg, 2 slices of wheat toast, orange juice, and coffee. Lunch consists of a chef salad most days with a sugar product.  Dinner consists of a lean meat, 1 serving of vegetables and a bowl of fresh fruit.

Family history: Mediterranean decent, father died at age 70 of heart disease, mother died at 79 also of heart disease as a complication of diabetes and hypertension. Her sister is still alive and healthy, and brother is diagnosed with heart disease. 

Question: Based on this clinical history, what are some differential diagnoses you are considering?