Differential Diagnosis for a 35-year-old Female with Flank Pain, Bilateral Lower Abdominal Pain, Blurred Vision, and Lightheadedness

Single Most Likely Diagnosis

• Pregnancy-related complications: Given the patient's age and symptoms, pregnancy-related complications such as ectopic pregnancy or miscarriage could be considered, especially if the patient is of childbearing age and has not used contraception or has a history of irregular menstrual cycles. The symptoms of flank pain, lower abdominal pain, and lightheadedness could be indicative of a pregnancy complication.

Other Likely Diagnoses

• Urinary Tract Infection (UTI) or Pyelonephritis: The symptoms of flank pain and lower abdominal pain could be indicative of a UTI or pyelonephritis, especially if the patient has a history of recurrent UTIs or has recently undergone a urinary tract procedure.
• Ovarian Cysts: Ovarian cysts could cause lower abdominal pain and could potentially cause flank pain if they are large enough to put pressure on surrounding structures.
• Kidney Stones: Kidney stones could cause severe flank pain and lower abdominal pain, especially if the stones are obstructing the flow of urine.

Do Not Miss Diagnoses

• Ectopic Pregnancy: Although mentioned as a possible single most likely diagnosis, ectopic pregnancy is a critical diagnosis that must not be missed due to its high mortality rate if left untreated.
• Appendicitis: Although the pain is bilateral, appendicitis can sometimes present with atypical symptoms and must be considered, especially if the patient has a history of abdominal surgery or has recently traveled.
• Sepsis: Sepsis is a life-threatening condition that can cause a wide range of symptoms, including abdominal pain, lightheadedness, and blurred vision, and must be considered, especially if the patient has a history of immunocompromised state or recent infection.

Rare Diagnoses

• Adrenal Insufficiency: Adrenal insufficiency is a rare condition that can cause a wide range of symptoms, including abdominal pain, lightheadedness, and blurred vision, especially if the patient has a history of autoimmune disorders or recent steroid use.
• Pheochromocytoma: Pheochromocytoma is a rare tumor of the adrenal gland that can cause episodic hypertension, abdominal pain, and lightheadedness, especially if the patient has a family history of the condition.
• Systemic Lupus Erythematosus (SLE): SLE is a rare autoimmune disorder that can cause a wide range of symptoms, including abdominal pain, lightheadedness, and blurred vision, especially if the patient has a history of autoimmune disorders or recent infection.